scripted-diff: Rename ShowModalDialogAndDeleteOnClose

-BEGIN VERIFY SCRIPT-
sed -i 's/ShowModalDialogAndDeleteOnClose/ShowModalDialogAsynchronously/' -- $(git grep -l -e "ShowModalDialogAndDeleteOnClose")
-END VERIFY SCRIPT-

It is important to highlight that a modal dialog is showed
asynchronously as there are cases when the synchronous QDialog::exec()
is required.

src/qt/sendcoinsdialog.cpp

@@ -930,7 +930,7 @@ void SendCoinsDialog::coinControlButtonClicked()
 {
     auto dlg = new CoinControlDialog(*m_coin_control, model, platformStyle);
     connect(dlg, &QDialog::finished, this, &SendCoinsDialog::coinControlUpdateLabels);
-    GUIUtil::ShowModalDialogAndDeleteOnClose(dlg);
+    GUIUtil::ShowModalDialogAsynchronously(dlg);
 }
 
 // Coin Control: checkbox custom change address