5d0c49f0e0
These actions are defined in the JSON files themselves, allowing us to migrate away from the sets of pre/post default keys, and fold them into the JSON files for fuller control on layout and appearance. As a first migration step, handle the relevant actions in the buttons created from the JSON files, so we can port these. Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2278>