Move the status setting and resetting back into handleClose so that we
don't end up with it being set if handleClose is never called in response
to a close attempt. This can happen when QWindow's platform window has
already been destroyed.
Since QWindow::close handles that case gracefully and returns true,
we can safely call it multiple times.
Add test coverage to verify that we get exactly those close event
calls that we want.
Change-Id: Ica77bf17c26d923c3b79b1e5a688addbc88a6277
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
bedc588698