move-only: Move CBlockFileInfo to kernel namespace

diff --git a/src/chain.cpp b/src/chain.cpp
index 3dd22634..94be7180 100644
--- a/src/chain.cpp
+++ b/src/chain.cpp
@@ -6,12 +6,6 @@
 #include <chain.h>
 #include <tinyformat.h>
 #include <util/check.h>
-#include <util/time.h>
-
-std::string CBlockFileInfo::ToString() const
-{
-    return strprintf("CBlockFileInfo(blocks=%u, size=%u, heights=%u...%u, time=%s...%s)", nBlocks, nSize, nHeightFirst, nHeightLast, FormatISO8601Date(nTimeFirst), FormatISO8601Date(nTimeLast));
-}
 
 std::string CBlockIndex::ToString() const
 {
diff --git a/src/chain.h b/src/chain.h
index 2c865265..64c86357 100644
--- a/src/chain.h
+++ b/src/chain.h
@@ -47,47 +47,6 @@ static constexpr int32_t SEQ_ID_INIT_FROM_DISK = 1;
  */
 static constexpr int64_t MAX_BLOCK_TIME_GAP = 90 * 60;
 
-class CBlockFileInfo
-{
-public:
-    unsigned int nBlocks{};      //!< number of blocks stored in file
-    unsigned int nSize{};        //!< number of used bytes of block file
-    unsigned int nUndoSize{};    //!< number of used bytes in the undo file
-    unsigned int nHeightFirst{}; //!< lowest height of block in file
-    unsigned int nHeightLast{};  //!< highest height of block in file
-    uint64_t nTimeFirst{};       //!< earliest time of block in file
-    uint64_t nTimeLast{};        //!< latest time of block in file
-
-    SERIALIZE_METHODS(CBlockFileInfo, obj)
-    {
-        READWRITE(VARINT(obj.nBlocks));
-        READWRITE(VARINT(obj.nSize));
-        READWRITE(VARINT(obj.nUndoSize));
-        READWRITE(VARINT(obj.nHeightFirst));
-        READWRITE(VARINT(obj.nHeightLast));
-        READWRITE(VARINT(obj.nTimeFirst));
-        READWRITE(VARINT(obj.nTimeLast));
-    }
-
-    CBlockFileInfo() = default;
-
-    std::string ToString() const;
-
-    /** update statistics (does not update nSize) */
-    void AddBlock(unsigned int nHeightIn, uint64_t nTimeIn)
-    {
-        if (nBlocks == 0 || nHeightFirst > nHeightIn)
-            nHeightFirst = nHeightIn;
-        if (nBlocks == 0 || nTimeFirst > nTimeIn)
-            nTimeFirst = nTimeIn;
-        nBlocks++;
-        if (nHeightIn > nHeightLast)
-            nHeightLast = nHeightIn;
-        if (nTimeIn > nTimeLast)
-            nTimeLast = nTimeIn;
-    }
-};
-
 enum BlockStatus : uint32_t {
     //! Unused.
     BLOCK_VALID_UNKNOWN      =    0,
diff --git a/src/node/blockstorage.cpp b/src/node/blockstorage.cpp
index e1b54175..20ace666 100644
--- a/src/node/blockstorage.cpp
+++ b/src/node/blockstorage.cpp
@@ -35,6 +35,7 @@
 #include <util/signalinterrupt.h>
 #include <util/strencodings.h>
 #include <util/syserror.h>
+#include <util/time.h>
 #include <util/translation.h>
 #include <validation.h>
 
@@ -151,6 +152,11 @@ bool BlockTreeDB::LoadBlockIndexGuts(const Consensus::Params& consensusParams, s
 
     return true;
 }
+
+std::string CBlockFileInfo::ToString() const
+{
+    return strprintf("CBlockFileInfo(blocks=%u, size=%u, heights=%u...%u, time=%s...%s)", nBlocks, nSize, nHeightFirst, nHeightLast, FormatISO8601Date(nTimeFirst), FormatISO8601Date(nTimeLast));
+}
 } // namespace kernel
 
 namespace node {
diff --git a/src/node/blockstorage.h b/src/node/blockstorage.h
index cee0eb61..e4d208c1 100644
--- a/src/node/blockstorage.h
+++ b/src/node/blockstorage.h
@@ -47,6 +47,47 @@ class SignalInterrupt;
 } // namespace util
 
 namespace kernel {
+class CBlockFileInfo
+{
+public:
+    unsigned int nBlocks{};      //!< number of blocks stored in file
+    unsigned int nSize{};        //!< number of used bytes of block file
+    unsigned int nUndoSize{};    //!< number of used bytes in the undo file
+    unsigned int nHeightFirst{}; //!< lowest height of block in file
+    unsigned int nHeightLast{};  //!< highest height of block in file
+    uint64_t nTimeFirst{};       //!< earliest time of block in file
+    uint64_t nTimeLast{};        //!< latest time of block in file
+
+    SERIALIZE_METHODS(CBlockFileInfo, obj)
+    {
+        READWRITE(VARINT(obj.nBlocks));
+        READWRITE(VARINT(obj.nSize));
+        READWRITE(VARINT(obj.nUndoSize));
+        READWRITE(VARINT(obj.nHeightFirst));
+        READWRITE(VARINT(obj.nHeightLast));
+        READWRITE(VARINT(obj.nTimeFirst));
+        READWRITE(VARINT(obj.nTimeLast));
+    }
+
+    CBlockFileInfo() = default;
+
+    std::string ToString() const;
+
+    /** update statistics (does not update nSize) */
+    void AddBlock(unsigned int nHeightIn, uint64_t nTimeIn)
+    {
+        if (nBlocks == 0 || nHeightFirst > nHeightIn)
+            nHeightFirst = nHeightIn;
+        if (nBlocks == 0 || nTimeFirst > nTimeIn)
+            nTimeFirst = nTimeIn;
+        nBlocks++;
+        if (nHeightIn > nHeightLast)
+            nHeightLast = nHeightIn;
+        if (nTimeIn > nTimeLast)
+            nTimeLast = nTimeIn;
+    }
+};
+
 /** Access to the block database (blocks/index/) */
 class BlockTreeDB : public CDBWrapper
 {
@@ -65,6 +106,7 @@ public:
 } // namespace kernel
 
 namespace node {
+using kernel::CBlockFileInfo;
 using kernel::BlockTreeDB;
 
 /** The pre-allocation chunk size for blk?????.dat files (since 0.8) */
diff --git a/src/test/blockmanager_tests.cpp b/src/test/blockmanager_tests.cpp
index f06665d3..679ba815 100644
--- a/src/test/blockmanager_tests.cpp
+++ b/src/test/blockmanager_tests.cpp
@@ -17,6 +17,7 @@
 #include <test/util/logging.h>
 #include <test/util/setup_common.h>
 
+using kernel::CBlockFileInfo;
 using node::STORAGE_HEADER_BYTES;
 using node::BlockManager;
 using node::KernelNotifications;
diff --git a/src/test/fuzz/block_index.cpp b/src/test/fuzz/block_index.cpp
index eef8c2ef..5e7f789c 100644
--- a/src/test/fuzz/block_index.cpp
+++ b/src/test/fuzz/block_index.cpp
@@ -12,6 +12,8 @@
 #include <txdb.h>
 #include <validation.h>
 
+using kernel::CBlockFileInfo;
+
 namespace {
 
 const BasicTestingSetup* g_setup;
diff --git a/src/test/fuzz/deserialize.cpp b/src/test/fuzz/deserialize.cpp
index 05ca62b6..97985ef0 100644
--- a/src/test/fuzz/deserialize.cpp
+++ b/src/test/fuzz/deserialize.cpp
@@ -17,6 +17,7 @@
 #include <net.h>
 #include <netbase.h>
 #include <netgroup.h>
+#include <node/blockstorage.h>
 #include <node/utxo_snapshot.h>
 #include <primitives/block.h>
 #include <protocol.h>
@@ -34,6 +35,7 @@
 #include <optional>
 #include <stdexcept>
 
+using kernel::CBlockFileInfo;
 using node::SnapshotMetadata;
 
 namespace {