Delete QQuickWindow's animator driver at the right time.

Delete QQuickWindow's animator driver at the right time.

For the non-threaded renderloops, we there might be a timer firing
before the animationController is cleaned up through deleteLater()
which will then reference the deleted QQuickWindow. Rely instead on
direct and explicit cleanup at the right time in each render loop.

Change-Id: Id81daddae78ce3922d6a932fb21200f2dc7955bb
Task-number: QTBUG-33723
Reviewed-by: Liang Qi <liang.qi@theqtcompany.com>
Reviewed-by: Robin Burchell <robin.burchell@viroteck.net>