Add the Qt window module as an alternative to the SDL2 module

Att the Qt window module as an alternative to the SDL2 module

Description is TBD

src/module/qt_window/mpvwidget.cc

@@ -376,7 +376,7 @@ MpvWidget::keyPressEvent(QKeyEvent* event)
         case Qt::Key_I:
             MPV_SEND_COMMAND_ASYNC("script-binding", "stats/display-stats", NULL);
         case Qt::Key_Delete:
-            MPV_SEND_COMMAND_ASYNC("script-binding", "osc/visibility", NULL);
+            MPV_SEND_COMMAND_ASYNC("script-message", "osc-visibility", (m_oscVisible = !m_oscVisible) ? "always" : "never", NULL);
 
         default:
             break;