f2ca53b9e0
Move back actors that were adopted from mutter (window_group, top_window_group, the feedback group) from the uiGroup to the stage, and then destroy the uiGroup. This will tear down more or less all of GNOME Shells actors gracefully. Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1349>