qml: Show 4 proper indicators when dragging in a floating window

They don't do much yet, but at least appear.

src/private/indicators/ClassicIndicators_p.h

@@ -36,6 +36,7 @@ private:
     friend class KDDockWidgets::IndicatorWindow;
     void raiseIndicators();
     void setDropLocation(DropLocation);
+    void updateWindowPosition();
 
     QWidgetOrQuick *const m_rubberBand;
     IndicatorWindow *const m_indicatorWindow;