Support homed users
This MR (hopes to) make all the user management features gnome-control-center exposes for legacy/traditional user accounts work with homed user accounts.
Depends on https://gitlab.freedesktop.org/accountsservice/accountsservice/-/merge_requests/144 and https://gitlab.freedesktop.org/accountsservice/accountsservice/-/merge_requests/146
Edited by Adrian Vovk