Adds initial intermediate qt6 porting state

qt6-after/qt6-migrated-legatus/Lts/Plugins/AppStarter/app_gui_plugin_interface.h

@@ -0,0 +1,23 @@
+
+
+
+#pragma once
+
+#include <QObject>
+
+
+namespace AppStarter
+{
+
+class ForeignGuiInterface : public QObject
+{
+  Q_OBJECT
+
+public:
+  ForeignGuiInterface() = default;
+  virtual ~ForeignGuiInterface() = default;
+
+  static QString pluginName() { return QStringLiteral("AppStarterGui"); }
+};
+
+}