qt, qml: for new transaction notifications, instead of using sign, explicitly say sent/received. For multiple transactions, split summary in total sent/received and a balance change.

diff --git a/electrum/gui/qml/qewallet.py b/electrum/gui/qml/qewallet.py
index 314368a..443fca4 100644
--- a/electrum/gui/qml/qewallet.py
+++ b/electrum/gui/qml/qewallet.py
@@ -198,7 +198,7 @@ class QEWallet(AuthMixin, QObject, QtEventListener):
             self.invoiceStatusChanged.emit(key, status)
 
     @qt_event_listener
-    def on_event_new_transaction(self, wallet, tx):
+    def on_event_new_transaction(self, wallet: Abstract_Wallet, tx: Transaction):
         if wallet == self.wallet:
             self._logger.info(f'new transaction {tx.txid()}')
             self.add_tx_notification(tx)
@@ -258,7 +258,7 @@ class QEWallet(AuthMixin, QObject, QtEventListener):
     def on_destroy(self):
         self.unregister_callbacks()
 
-    def add_tx_notification(self, tx):
+    def add_tx_notification(self, tx: Transaction):
         self._logger.debug('new transaction event')
         self.tx_notification_queue.put(tx)
         if not self.notification_timer.isActive():
@@ -285,23 +285,8 @@ class QEWallet(AuthMixin, QObject, QtEventListener):
             except queue.Empty:
                 break
 
-        config = self.wallet.config
-        # Combine the transactions if there are at least three
-        if len(txns) >= 3:
-            total_amount = 0
-            for tx in txns:
-                tx_wallet_delta = self.wallet.get_wallet_delta(tx)
-                if not tx_wallet_delta.is_relevant:
-                    continue
-                total_amount += tx_wallet_delta.delta
-            self.userNotify.emit(self.wallet, _("{} new transactions: Total amount received in the new transactions {}").format(len(txns), config.format_amount_and_units(total_amount)))
-        else:
-            for tx in txns:
-                tx_wallet_delta = self.wallet.get_wallet_delta(tx)
-                if not tx_wallet_delta.is_relevant:
-                    continue
-                self.userNotify.emit(self.wallet,
-                    _("New transaction: {}").format(config.format_amount_and_units(tx_wallet_delta.delta)))
+        for notification in self.wallet.get_user_notifications_for_new_txns(txns):
+            self.userNotify.emit(self.wallet, notification)
 
     def update_sync_progress(self):
         if self.wallet.network and self.wallet.network.is_connected():
diff --git a/electrum/gui/qt/main_window.py b/electrum/gui/qt/main_window.py
index 6b85422..993a216 100644
--- a/electrum/gui/qt/main_window.py
+++ b/electrum/gui/qt/main_window.py
@@ -474,7 +474,7 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, Logger, QtEventListener):
             self.need_update.set()
 
     @event_listener
-    def on_event_new_transaction(self, wallet, tx):
+    def on_event_new_transaction(self, wallet: Abstract_Wallet, tx: Transaction):
         if wallet == self.wallet:
             self.tx_notification_queue.put(tx)
             self.need_update.set()
@@ -930,22 +930,9 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, Logger, QtEventListener):
                 txns.append(self.tx_notification_queue.get_nowait())
             except queue.Empty:
                 break
-        # Combine the transactions if there are at least three
-        if len(txns) >= 3:
-            total_amount = 0
-            for tx in txns:
-                tx_wallet_delta = self.wallet.get_wallet_delta(tx)
-                if not tx_wallet_delta.is_relevant:
-                    continue
-                total_amount += tx_wallet_delta.delta
-            self.notify(_("{} new transactions: Total amount received in the new transactions {}")
-                        .format(len(txns), self.format_amount_and_units(total_amount)))
-        else:
-            for tx in txns:
-                tx_wallet_delta = self.wallet.get_wallet_delta(tx)
-                if not tx_wallet_delta.is_relevant:
-                    continue
-                self.notify(_("New transaction: {}").format(self.format_amount_and_units(tx_wallet_delta.delta)))
+
+        for notification in self.wallet.get_user_notifications_for_new_txns(txns):
+            self.notify(notification)
 
     def notify(self, message):
         if self.tray:
diff --git a/electrum/wallet.py b/electrum/wallet.py
index ae116e9..de34105 100644
--- a/electrum/wallet.py
+++ b/electrum/wallet.py
@@ -3691,6 +3691,43 @@ class Abstract_Wallet(ABC, Logger, EventListener):
             else:
                 f.write(util.json_encode(txns))
 
+    def get_user_notifications_for_new_txns(self, txns: Sequence[Transaction]) -> Sequence[str]:
+        notifications = []
+        # Combine the transactions if there are at least three
+        if len(txns) >= 3:
+            total_amount = 0
+            total_debit = 0
+            total_credit = 0
+            for tx in txns:
+                tx_wallet_delta = self.get_wallet_delta(tx)
+                if not tx_wallet_delta.is_relevant:
+                    continue
+                if tx_wallet_delta.delta < 0:
+                    total_debit += -tx_wallet_delta.delta
+                else:
+                    total_credit += tx_wallet_delta.delta
+                total_amount += tx_wallet_delta.delta
+            message = _('{} new transactions:').format(len(txns))
+            if total_debit:
+                message += '\n' + _('Total amount sent {}').format(self.config.format_amount_and_units(total_debit))
+            if total_credit:
+                message += '\n' + _('Total amount received {}').format(self.config.format_amount_and_units(total_credit))
+            if total_debit and total_credit:
+                message += '\n' + _('Total balance change: {}').format(self.config.format_amount_and_units(total_amount))
+            notifications.append(message)
+        else:
+            for tx in txns:
+                tx_wallet_delta = self.get_wallet_delta(tx)
+                if not tx_wallet_delta.is_relevant:
+                    continue
+                if tx_wallet_delta.delta < 0:
+                    message = _('sent {}').format(self.config.format_amount_and_units(-tx_wallet_delta.delta))
+                else:
+                    message = _('received {}').format(self.config.format_amount_and_units(tx_wallet_delta.delta))
+                message = _("New transaction: {}").format(message)
+                notifications.append(message)
+        return notifications
+
 
 class Simple_Wallet(Abstract_Wallet):
     # wallet with a single keystore