monitor: Keep track of the for lease status

Add a flag to MetaMonitor indicating if the monitor is available for
lease and store/update it from the monitor configuration.

Also, add unit tests validating that the configuration is applied and
that invalid configurations fail.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/4112>

src/backends/native/meta-monitor-manager-native.c

@@ -156,6 +156,7 @@ meta_monitor_manager_native_ensure_initial_config (MetaMonitorManager *manager)
   config = meta_monitor_manager_ensure_configured (manager);
 
   meta_monitor_manager_update_logical_state (manager, config);
+  meta_monitor_manager_update_for_lease_state (manager, config);
 }
 
 static void