APE cache non cacheable response

Issue
We have found JsonResponse used in our custom module and AjaxResponse used in autocomplete field are cached after we enabled APE module. It turns out APE event subscriber does not check if the response is cacheable or not. So it probably would cache all plain response including JsonResponse, AjaxResponse, RedirectionResponse, and etc.

Solution
Check if the response implements CacheableResponseInterface interface like dynamic_page_cache module does.

    if (!$response instanceof CacheableResponseInterface) {
      return;
    }