clutter: Do not check redraw area for pointer repicks

This looks like a relic of glReadPixels-based picking, the pointer might well be outside redrawn areas, yet still require a device update (e.g. in order to reflect the actor layout changes in the "clear area" info).

Instead, always update all devices that are inside the view after relayouts, the tracking on the need for that update is now done on each ClutterStageView, instead of globally in the ClutterStage.

This theoretically fixes situations where pointers might miss updating their "clear area" after the actor tree changed.

Related: #2117 (closed)