After porting the more complex cases - in particular those that
affect a module's API - we are left with straight-forward D-Bus
method calls that can be moved to promise-based wrappers in one
go.
For consistency, this also switches from Remote to Async where
the call result is ignored.
Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2344>