qt: Send dialog status to VM-manager & fix pause

- Manager is notified of modal dialogs blocking the main window.
- Pause command from manager uses action to prevent desyncing pause status
in the menus and toolbar.

src/qt/qt_mainwindow.cpp

@@ -1500,4 +1500,9 @@ void MainWindow::showSettings()
 void MainWindow::hardReset()
 {
     ui->actionHard_Reset->trigger();
+}
+
+void MainWindow::togglePause()
+{
+    ui->actionPause->trigger();
 }