7e18fc1b1f
This is based on gtksink, but similar to waylandsink uses Wayland APIs directly instead of rendering with Gtk/Cairo primitives. Note that the long term plan is to move this into the existing extension in `-good`, which requires the Wayland library to move the as well. For this reason several files like `gstgtkutils.*` and `gtkgstbasewidget.*` are straight copies and should be kept in sync. Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1515>