Mouse Hover events aren't propagated to elements under a PinchArea on Mac OS

On Mac OS QQuickPinchArea registers itself to receive hover events. This prevents other items below the pinch area from receiving those same events. On other platforms they do receive those events. This is an incompatibility between platforms. As the pinch area only uses the events to figure out when to register itself for touch events there's no real reason to keep receiving them afterwards, even on Mac OS. The same holds for MultiPointTouchArea.