Rémi Denis-Courmont authored May 03, 2022 and Hugo Beauzée-Luyssen committed May 05, 2022

This moves what was left of mouse event processing out of the video
output thread. Thus mouse events are processed directly from the
emitting thread (UI for embedded video, window provider otherwise),
just like keyboard events.

This removes the lesser bottleneck in mouse event processing (the
bigger bottleneck being the display lock to be removed further on).

Incidentally, this also removes the last remaining event type from the
video output queue.