qt: Move transaction notification to transaction table model

Move transaction new/update notification to TransactionTableModel.
This moves the concerns to where they're actually handled.
No need to bounce this through wallet model.

- Do wallet transaction preprocessing on signal handler side;
  avoids locking cs_main/cs_wallet on notification in GUI thread
  (except for new transactions)

src/qt/transactiontablemodel.h

@@ -72,12 +72,17 @@ public:
     QVariant data(const QModelIndex &index, int role) const;
     QVariant headerData(int section, Qt::Orientation orientation, int role) const;
     QModelIndex index(int row, int column, const QModelIndex & parent = QModelIndex()) const;
+    bool processingQueuedTransactions() { return fProcessingQueuedTransactions; }
 
 private:
     CWallet* wallet;
     WalletModel *walletModel;
     QStringList columns;
     TransactionTablePriv *priv;
+    bool fProcessingQueuedTransactions;
+
+    void subscribeToCoreSignals();
+    void unsubscribeFromCoreSignals();
 
     QString lookupAddress(const std::string &address, bool tooltip) const;
     QVariant addressColor(const TransactionRecord *wtx) const;
@@ -92,11 +97,14 @@ private:
     QVariant txAddressDecoration(const TransactionRecord *wtx) const;
 
 public slots:
-    void updateTransaction(const QString &hash, int status);
+    /* New transaction, or transaction changed status */
+    void updateTransaction(const QString &hash, int status, bool showTransaction);
     void updateConfirmations();
     void updateDisplayUnit();
     /** Updates the column title to "Amount (DisplayUnit)" and emits headerDataChanged() signal for table headers to react. */
     void updateAmountColumnTitle();
+    /* Needed to update fProcessingQueuedTransactions through a QueuedConnection */
+    void setProcessingQueuedTransactions(bool value) { fProcessingQueuedTransactions = value; }
 
     friend class TransactionTablePriv;
 };