Add inhibit_fullscreen command

inhibit_fullscreen allows a container to service but ignore fullscreen
requests from clients. This allows clients to change to fullscreen mode
without changing dimensions of its container.

sway/desktop/xdg_shell.c

@@ -363,7 +363,7 @@ static void handle_request_fullscreen(struct wl_listener *listener, void *data)
 		}
 	}
 
-	container_set_fullscreen(view->container, e->fullscreen);
+	container_request_fullscreen(view->container, e->fullscreen);
 
 	arrange_root();
 	transaction_commit_dirty();