win: rename find_toplevel_nocache to find_managed_window_or_parent

My previous understanding of this function is incorrect. Hopefully I got
it right this time.

Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>

src/win.c

@@ -2189,13 +2189,13 @@ struct managed_win *find_toplevel(session_t *ps, xcb_window_t id) {
 }
 
 /**
- * Find out the WM frame of a client window by querying X.
+ * Find a managed window that is, or is a parent of `wid`.
  *
  * @param ps current session
  * @param wid window ID
  * @return struct _win object of the found window, NULL if not found
  */
-struct managed_win *find_toplevel_nocache(session_t *ps, xcb_window_t wid) {
+struct managed_win *find_managed_window_or_parent(session_t *ps, xcb_window_t wid) {
 	// TODO this should probably be an "update tree", then find_toplevel.
 	//      current approach is a bit more "racy"
 	struct win *w = NULL;