When re-negotiation happends and caps is changed, resize the viewport to the corresponding video size in changed caps. Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/7341>
It's the same enum, just drop the renamed copy. But keep the registered GEnum as it is part of the API. Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1088>