Merge bitcoin/bitcoin#35513: rpc: help metadata fixes

### src/rpc/blockchain.cpp
@@ -1220,7 +1220,7 @@ static RPCMethod gettxout()
         "gettxout",
         "Returns details about an unspent transaction output.\n",
         {
-            {"txid", RPCArg::Type::STR, RPCArg::Optional::NO, "The transaction id"},
+            {"txid", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "The transaction id"},
             {"n", RPCArg::Type::NUM, RPCArg::Optional::NO, "vout number"},
             {"include_mempool", RPCArg::Type::BOOL, RPCArg::Default{true}, "Whether to include the mempool. Note that an unspent output that is spent in the mempool won't appear."},
         },

### src/rpc/fees.cpp
@@ -172,7 +172,7 @@ static std::vector<RPCResult> FeeEstimateHorizonDoc(bool elide = false)
         {RPCResult::Type::OBJ, "fail", /*optional=*/true, "information about the highest range of feerates to fail to meet the threshold", FeeRateBucketDoc(/*elide=*/true)},
         {RPCResult::Type::ARR, "errors", /*optional=*/true, "Errors encountered during processing (if there are any)",
         {
-            {RPCResult::Type::STR, "error", ""},
+            {RPCResult::Type::STR, "", "error"},
         }},
     };
     return elide ? ElideGroup(std::move(fields)) : fields;

### src/rpc/mempool.cpp
@@ -474,7 +474,7 @@ static std::vector<RPCResult> ClusterDescription()
         RPCResult{RPCResult::Type::ARR, "chunks", "chunks in this cluster (in mining order)",
             {RPCResult{RPCResult::Type::OBJ, "chunk", "",
                 {
-                    RPCResult{RPCResult::Type::NUM, "chunkfee", "fees of the transactions in this chunk"},
+                    RPCResult{RPCResult::Type::STR_AMOUNT, "chunkfee", "fees of the transactions in this chunk"},
                     RPCResult{RPCResult::Type::NUM, "chunkweight", "sigops-adjusted weight of all transactions in this chunk"},
                     RPCResult{RPCResult::Type::ARR, "txs", "transactions in this chunk in mining order",
                         {RPCResult{RPCResult::Type::STR_HEX, "txid", "transaction id"}}},
@@ -685,7 +685,7 @@ static RPCMethod getmempoolfeeratediagram()
                         RPCResult::Type::OBJ, "", "",
                         {
                             {RPCResult::Type::NUM, "weight", "cumulative sigops-adjusted weight"},
-                            {RPCResult::Type::NUM, "fee", "cumulative fee"}
+                            {RPCResult::Type::STR_AMOUNT, "fee", "cumulative fee"}
                         }
                     }
                 }
@@ -1146,7 +1146,7 @@ static RPCMethod getmempoolinfo()
                     {RPCResult::Type::NUM, "maxmempool", "Maximum memory usage for the mempool"},
                     {RPCResult::Type::STR_AMOUNT, "mempoolminfee", "Minimum fee rate in " + CURRENCY_UNIT + "/kvB for tx to be accepted. Is the maximum of minrelaytxfee and minimum mempool fee"},
                     {RPCResult::Type::STR_AMOUNT, "minrelaytxfee", "Current minimum relay fee for transactions"},
-                    {RPCResult::Type::NUM, "incrementalrelayfee", "minimum fee rate increment for mempool limiting or replacement in " + CURRENCY_UNIT + "/kvB"},
+                    {RPCResult::Type::STR_AMOUNT, "incrementalrelayfee", "minimum fee rate increment for mempool limiting or replacement in " + CURRENCY_UNIT + "/kvB"},
                     {RPCResult::Type::NUM, "unbroadcastcount", "Current number of transactions that haven't passed initial broadcast yet"},
                     {RPCResult::Type::BOOL, "permitbaremultisig", "True if the mempool accepts transactions with bare multisig outputs"},
                     {RPCResult::Type::NUM, "maxdatacarriersize", "Maximum number of bytes that can be used by OP_RETURN outputs in the mempool"},

### src/rpc/net.cpp
@@ -199,7 +199,7 @@ static RPCMethod getpeerinfo()
                     {
                         {RPCResult::Type::STR, "permission_type", Join(NET_PERMISSIONS_DOC, ",\n") + ".\n"},
                     }},
-                    {RPCResult::Type::NUM, "minfeefilter", "The minimum fee rate for transactions this peer accepts"},
+                    {RPCResult::Type::STR_AMOUNT, "minfeefilter", "The minimum fee rate for transactions this peer accepts"},
                     {RPCResult::Type::OBJ_DYN, "bytessent_per_msg", "",
                     {
                         {RPCResult::Type::NUM, "msg", "The total bytes sent aggregated by message type\n"
@@ -709,8 +709,8 @@ static RPCMethod getnetworkinfo()
                                 {RPCResult::Type::BOOL, "proxy_randomize_credentials", "Whether randomized credentials are used"},
                             }},
                         }},
-                        {RPCResult::Type::NUM, "relayfee", "minimum relay fee rate for transactions in " + CURRENCY_UNIT + "/kvB"},
-                        {RPCResult::Type::NUM, "incrementalfee", "minimum fee rate increment for mempool limiting or replacement in " + CURRENCY_UNIT + "/kvB"},
+                        {RPCResult::Type::STR_AMOUNT, "relayfee", "minimum relay fee rate for transactions in " + CURRENCY_UNIT + "/kvB"},
+                        {RPCResult::Type::STR_AMOUNT, "incrementalfee", "minimum fee rate increment for mempool limiting or replacement in " + CURRENCY_UNIT + "/kvB"},
                         {RPCResult::Type::ARR, "localaddresses", "list of local addresses",
                         {
                             {RPCResult::Type::OBJ, "", "",
@@ -742,40 +742,34 @@ static RPCMethod getnetworkinfo()
     obj.pushKV("subversion",    strSubVersion);
     obj.pushKV("protocolversion",PROTOCOL_VERSION);
     NodeContext& node = EnsureAnyNodeContext(request.context);
-    if (node.connman) {
-        ServiceFlags services = node.connman->GetLocalServices();
-        obj.pushKV("localservices", strprintf("%016x", services));
-        obj.pushKV("localservicesnames", GetServicesNames(services));
-    }
-    if (node.peerman) {
-        auto peerman_info{node.peerman->GetInfo()};
-        obj.pushKV("localrelay", !peerman_info.ignores_incoming_txs);
-        obj.pushKV("timeoffset", Ticks<std::chrono::seconds>(peerman_info.median_outbound_time_offset));
-        obj.pushKV("tx_send_rate", peerman_info.tx_send_rate);
-        auto buckjson = [&](const auto& buckinfo) {
-            UniValue b{UniValue::VOBJ};
-            b.pushKV("backlog", buckinfo.backlog_count);
-            b.pushKV("count_tok", buckinfo.count_bucket);
-            b.pushKV("size_tok", buckinfo.size_bucket);
-            return b;
-        };
-        UniValue invbuckets{UniValue::VOBJ};
-        invbuckets.pushKV("inbound", buckjson(peerman_info.inbound_bucket));
-        invbuckets.pushKV("outbound", buckjson(peerman_info.outbound_bucket));
-        obj.pushKV("inv_buckets", invbuckets);
-    }
-    if (node.connman) {
-        obj.pushKV("networkactive", node.connman->GetNetworkActive());
-        obj.pushKV("connections", node.connman->GetNodeCount(ConnectionDirection::Both));
-        obj.pushKV("connections_in", node.connman->GetNodeCount(ConnectionDirection::In));
-        obj.pushKV("connections_out", node.connman->GetNodeCount(ConnectionDirection::Out));
-    }
+    CConnman& connman = EnsureConnman(node);
+    ServiceFlags services = connman.GetLocalServices();
+    obj.pushKV("localservices", strprintf("%016x", services));
+    obj.pushKV("localservicesnames", GetServicesNames(services));
+    auto peerman_info{EnsurePeerman(node).GetInfo()};
+    obj.pushKV("localrelay", !peerman_info.ignores_incoming_txs);
+    obj.pushKV("timeoffset", Ticks<std::chrono::seconds>(peerman_info.median_outbound_time_offset));
+    obj.pushKV("tx_send_rate", peerman_info.tx_send_rate);
+    auto buckjson = [&](const auto& buckinfo) {
+        UniValue b{UniValue::VOBJ};
+        b.pushKV("backlog", buckinfo.backlog_count);
+        b.pushKV("count_tok", buckinfo.count_bucket);
+        b.pushKV("size_tok", buckinfo.size_bucket);
+        return b;
+    };
+    UniValue invbuckets{UniValue::VOBJ};
+    invbuckets.pushKV("inbound", buckjson(peerman_info.inbound_bucket));
+    invbuckets.pushKV("outbound", buckjson(peerman_info.outbound_bucket));
+    obj.pushKV("inv_buckets", invbuckets);
+    obj.pushKV("networkactive", connman.GetNetworkActive());
+    obj.pushKV("connections", connman.GetNodeCount(ConnectionDirection::Both));
+    obj.pushKV("connections_in", connman.GetNodeCount(ConnectionDirection::In));
+    obj.pushKV("connections_out", connman.GetNodeCount(ConnectionDirection::Out));
     obj.pushKV("networks",      GetNetworksInfo());
-    if (node.mempool) {
-        // Those fields can be deprecated, to be replaced by the getmempoolinfo fields
-        obj.pushKV("relayfee", ValueFromAmount(node.mempool->m_opts.min_relay_feerate.GetFeePerK()));
-        obj.pushKV("incrementalfee", ValueFromAmount(node.mempool->m_opts.incremental_relay_feerate.GetFeePerK()));
-    }
+    const CTxMemPool& mempool = EnsureAnyMemPool(request.context);
+    // Those fields can be deprecated, to be replaced by the getmempoolinfo fields
+    obj.pushKV("relayfee", ValueFromAmount(mempool.m_opts.min_relay_feerate.GetFeePerK()));
+    obj.pushKV("incrementalfee", ValueFromAmount(mempool.m_opts.incremental_relay_feerate.GetFeePerK()));
     UniValue localAddresses(UniValue::VARR);
     {
         LOCK(g_maplocalhost_mutex);

### src/wallet/rpc/coins.cpp
@@ -490,7 +490,7 @@ RPCMethod listunspent()
                             {RPCResult::Type::NUM, "vout", "the vout value"},
                             {RPCResult::Type::STR, "address", /*optional=*/true, "the bitcoin address"},
                             {RPCResult::Type::STR, "label", /*optional=*/true, "The associated label, or \"\" for the default label"},
-                            {RPCResult::Type::STR, "scriptPubKey", "the output script"},
+                            {RPCResult::Type::STR_HEX, "scriptPubKey", "the output script"},
                             {RPCResult::Type::STR_AMOUNT, "amount", "the transaction output amount in " + CURRENCY_UNIT},
                             {RPCResult::Type::NUM, "confirmations", "The number of confirmations"},
                             {RPCResult::Type::NUM, "ancestorcount", /*optional=*/true, "The number of in-mempool ancestor transactions, including this one (if transaction is in the mempool)"},

### src/wallet/rpc/transactions.cpp
@@ -426,7 +426,7 @@ static std::vector<RPCResult> TransactionDescriptionString()
            {RPCResult::Type::STR, "comment", /*optional=*/true, "If a comment is associated with the transaction, only present if not empty."},
            {RPCResult::Type::STR, "bip125-replaceable", /*optional=*/true, "(\"yes|no|unknown\") (DEPRECATED) Whether this transaction signals BIP125 replaceability or has an unconfirmed ancestor signaling BIP125 replaceability.\n"
                "May be unknown for unconfirmed transactions not in the mempool because their unconfirmed ancestors are unknown."},
-           {RPCResult::Type::ARR, "parent_descs", /*optional=*/true, "Only if 'category' is 'received'. List of parent descriptors for the output script of this coin.", {
+           {RPCResult::Type::ARR, "parent_descs", /*optional=*/true, "Only if 'category' is 'receive'. List of parent descriptors for the output script of this coin.", {
                {RPCResult::Type::STR, "desc", "The descriptor string."},
            }},
            };
@@ -726,7 +726,7 @@ RPCMethod gettransaction()
                                 {RPCResult::Type::STR_AMOUNT, "fee", /*optional=*/true, "The amount of the fee in " + CURRENCY_UNIT + ". This is negative and only available for the \n"
                                     "'send' category of transactions."},
                                 {RPCResult::Type::BOOL, "abandoned", "'true' if the transaction has been abandoned (inputs are respendable)."},
-                                {RPCResult::Type::ARR, "parent_descs", /*optional=*/true, "Only if 'category' is 'received'. List of parent descriptors for the output script of this coin.", {
+                                {RPCResult::Type::ARR, "parent_descs", /*optional=*/true, "Only if 'category' is 'receive'. List of parent descriptors for the output script of this coin.", {
                                     {RPCResult::Type::STR, "desc", "The descriptor string."},
                                 }},
                             }},

### src/wallet/rpc/wallet.cpp
@@ -54,7 +54,7 @@ static RPCMethod getwalletinfo()
                         {RPCResult::Type::STR, "format", "the database format (only sqlite)"},
                         {RPCResult::Type::NUM, "txcount", "the total number of transactions in the wallet"},
                         {RPCResult::Type::NUM, "keypoolsize", "how many new keys are pre-generated (only counts external keys)"},
-                        {RPCResult::Type::NUM, "keypoolsize_hd_internal", /*optional=*/true, "how many new keys are pre-generated for internal use (used for change outputs, only appears if the wallet is using this feature, otherwise external keys are used)"},
+                        {RPCResult::Type::NUM, "keypoolsize_hd_internal", "how many new keys are pre-generated for internal use (used for change outputs; 0 if external keys are used for change)"},
                         {RPCResult::Type::NUM_TIME, "unlocked_until", /*optional=*/true, "the " + UNIX_EPOCH_TIME + " until which the wallet is unlocked for transfers, or 0 if the wallet is locked (only present for passphrase-encrypted wallets)"},
                         {RPCResult::Type::BOOL, "private_keys_enabled", "false if privatekeys are disabled for this wallet (enforced watch-only wallet)"},
                         {RPCResult::Type::BOOL, "avoid_reuse", "whether this wallet tracks clean/dirty coins in terms of reuse"},
@@ -155,7 +155,7 @@ static RPCMethod listwalletdir()
                             {RPCResult::Type::OBJ, "", "",
                             {
                                 {RPCResult::Type::STR, "name", "The wallet name"},
-                                {RPCResult::Type::ARR, "warnings", /*optional=*/true, "Warning messages, if any, related to loading the wallet.",
+                                {RPCResult::Type::ARR, "warnings", "Warning messages related to loading the wallet (may be empty).",
                                 {
                                     {RPCResult::Type::STR, "", ""},
                                 }},
@@ -501,7 +501,7 @@ RPCMethod simulaterawtransaction()
         "simulaterawtransaction",
         "Calculate the balance change resulting in the signing and broadcasting of the given transaction(s).\n",
         {
-            {"rawtxs", RPCArg::Type::ARR, RPCArg::Optional::OMITTED, "An array of hex strings of raw transactions.\n",
+            {"rawtxs", RPCArg::Type::ARR, RPCArg::Optional::NO, "An array of hex strings of raw transactions.\n",
                 {
                     {"rawtx", RPCArg::Type::STR_HEX, RPCArg::Optional::OMITTED, ""},
                 },