df84854d90
When opening a session, find if there's already a session opened for the same user with the help of Loginmanager. When it's found, display the conflicting session dialog. The logout dialog allows shutting down the conflicting session using the greeter dbus method "StopConflictingSession". If the dialog is already opened and the conflicting session has been closed on its side, the new session will start. Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/3134>