Adds initial intermediate qt6 porting state

qt6-after/qt6-migrated-legatus/Lts/Common/LtsMultiMonitor/lts_dummy_widget.h

@@ -0,0 +1,43 @@
+#pragma once
+
+#include <LtsMultiMonitor/lts_multi_monitor_export.h>
+
+#include <QWidget>
+
+
+class QEvent;
+
+
+namespace LtsMultiMonitor
+{
+
+class LTSMULTIMONITOR_EXPORT SecondaryWidget : public QWidget
+{
+  Q_OBJECT
+public:
+  SecondaryWidget() = default;
+  virtual ~SecondaryWidget() = default;
+};
+
+
+
+class LTSMULTIMONITOR_EXPORT FullscreenVideoDummyWidget : public SecondaryWidget
+{
+  Q_OBJECT
+
+public:
+  FullscreenVideoDummyWidget();
+
+  void hideVideo();
+  void showVideo();
+
+protected:
+  bool event(QEvent *);
+
+signals:
+  void signalWidgetPlaced(const QRect &globalGeometry);
+  void signalHideVideo();
+  void signalShowVideo();
+};
+
+}