Fix the popup position of a Menu

QPA code should operate in native coord.

Treat QWidgetPlatformMenu::showPopup's input as native coord.

Fixes: QTBUG-94619 Fixes: QTBUG-94783

Change-Id: Iaa030c96d84e4a588e625fe191e4324f70be961f

Reviewed-by: Morten Johan Sørvig morten.sorvig@qt.io

(cherry picked from commit f8cf17166c9af147f0b8fea72f5b4a8a6098a5d7 in qtdeclarative)

Merged upstream at https://codereview.qt-project.org/c/qt/qtdeclarative/+/428183