qt: Handle exceptions in SendCoinsDialog::sendButtonClicked slot

Also, uic automatic connection replaced with an explicit one.

src/qt/sendcoinsdialog.cpp

@@ -129,6 +129,8 @@ SendCoinsDialog::SendCoinsDialog(const PlatformStyle *_platformStyle, QWidget *p
     ui->customFee->SetAllowEmpty(false);
     ui->customFee->setValue(settings.value("nTransactionFee").toLongLong());
     minimizeFeeSection(settings.value("fFeeSectionMinimized").toBool());
+
+    GUIUtil::ExceptionSafeConnect(ui->sendButton, &QPushButton::clicked, this, &SendCoinsDialog::sendButtonClicked);
 }
 
 void SendCoinsDialog::setClientModel(ClientModel *_clientModel)
@@ -375,7 +377,7 @@ bool SendCoinsDialog::PrepareSendText(QString& question_string, QString& informa
     return true;
 }
 
-void SendCoinsDialog::on_sendButton_clicked()
+void SendCoinsDialog::sendButtonClicked([[maybe_unused]] bool checked)
 {
     if(!model || !model->getOptionsModel())
         return;

src/qt/sendcoinsdialog.h

@@ -80,7 +80,7 @@ private:
     void updateCoinControlState(CCoinControl& ctrl);
 
 private Q_SLOTS:
-    void on_sendButton_clicked();
+    void sendButtonClicked(bool checked);
     void on_buttonChooseFee_clicked();
     void on_buttonMinimizeFee_clicked();
     void removeEntry(SendCoinsEntry* entry);

src/qt/test/wallettests.cpp

@@ -73,7 +73,7 @@ uint256 SendCoins(CWallet& wallet, SendCoinsDialog& sendCoinsDialog, const CTxDe
         if (status == CT_NEW) txid = hash;
     }));
     ConfirmSend();
-    bool invoked = QMetaObject::invokeMethod(&sendCoinsDialog, "on_sendButton_clicked");
+    bool invoked = QMetaObject::invokeMethod(&sendCoinsDialog, "sendButtonClicked", Q_ARG(bool, false));
     assert(invoked);
     return txid;
 }