VLCVideoUIView: fix window event reporting

The event reporting was broken and only worked on some specific unique-event cases. In particular, it was totally broken with resizing (which is not visible in the current codebase because the resizing events are not forwarded to the core, it's changed in another branch that I'll send).

Multiple events could be executed at the same time, in the wrong order, without the CFRunLoop mechanism waiting for their processing, which will result in jerky resize to invalid size if left as-is before the resize changes.

More details in $commits.