Unlike on macOS, our UIViews are children of a QIOSDesktopManagerView
that we use to do window management, so we need to remove the view
from its superview, even if represents a top level QWindow.
The only exception is top level foreign windows, which are used to
represent a native UIView for the purpose of containing a Qt view
hierarchy within. As we don't know anything about the foreign view's
superview hiearchy we shouldn't touch it.
Pick-to: 6.7 6.6
Fixes: QTBUG-120369
Change-Id: I6a43bb0a4e72d0d1525a7cc33d572ea7477215b3
Reviewed-by: Doris Verria <doris.verria@qt.io>
bc7e728fcf