feat: add flag to enable/disable Qt touch event processing

As Qt touch event will automatically be translated to mouse event, so the mouse event will be processed twice for one touch. So for some native vtk widget, such as vtkDistanceWidget, it designed behavior is broken on Qt6 platform. (By wrong use of QTouchEvent::TouchPoint::id(), the touch event is not processed accidentally with Qt5). So I add this flag for QVTKOpenGL*Widget to switch on/off the Qt touch event processing.