fix(api/buffer): fix handling of viewport of non-current buffer

A lot of functions in move.c only worked for curwin, alternatively
took a `wp` arg but still only work if that happens to be curwin.

Refactor those that are needed for update_topline(wp) to work
for any window.

fixes #27723
fixes #27720

src/nvim/lua/executor.c

@@ -1797,7 +1797,7 @@ void ex_luado(exarg_T *const eap)
   }
 
   lua_pop(lstate, 1);
-  check_cursor();
+  check_cursor(curwin);
   redraw_curbuf_later(UPD_NOT_VALID);
 }