video-stage paused and autoplay redundant

[johndigital]

I don't think we need both autoplay and paused, we should probably just have one prop called playing. We'll need to make sure it's fully reactive, so hardcoding playing to a truthy value would trigger an autoplay and toggling it after the component has already mounted would result in play/pause commands on the vimeo player.

When implemented, we should also keep autoplay and paused in there for a few versions for compatibility.