Add API to add and remove ClutterTimeline objects to the frame clock.
Just as the legacy master clock, having a timeline added to the frame
clock causes the frame clock to continuously reschedule updates until
the timeline is removed.
ClutterTimeline is adapted to be able to be driven by a
ClutterFrameClock. This is done by adding a 'frame-clock' property, and
if set, the timeline will add and remove itself to the frame clock
instead of the master clock.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1285