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_interface.cc

@@ -61,3 +61,10 @@ ___module_qt_window_toggle_pause(struct module_qt_window_s *win)
 {
     return win->mpv_widget->toggle_pause();
 }
+
+bool
+___module_qt_window_close(struct module_qt_window_s *win)
+{
+    delete(win->main_window);
+    return true;
+}