[Needs Feedback] Add PyQt6. Remove PyQt4

- fully qualify enum values for Qt6
- add resource file per Qt version
- TabWidget: use QPointF instead of QPoint for constructing mouse event

Change-Id: I07da61c36c4228a60f6b5b9dacbead27c0a2409d
Reviewed-on: https://forge.frm2.tum.de/review/c/secop/frappy/+/30585
Tested-by: Jenkins Automated Tests <pedersen+jenkins@frm2.tum.de>
Reviewed-by: Enrico Faulhaber <enrico.faulhaber@frm2.tum.de>
Reviewed-by: Alexander Zaft <a.zaft@fz-juelich.de>

bin/frappy-cfg-editor

@@ -40,7 +40,7 @@ def main(argv=None):
     app = QApplication(argv)
     window = MainWindow(args.file)
     window.show()
-    return app.exec_()
+    return app.exec()
 
 
 if __name__ == '__main__':

bin/frappy-gui

@@ -72,7 +72,7 @@ def main(argv=None):
     app.aboutToQuit.connect(win._onQuit)
     win.show()
 
-    return app.exec_()
+    return app.exec()
 
 
 if __name__ == '__main__':