Image field with the format 'URL to image' JSON response not correct

The patch '3367894_2.patch' fixes the issue, now the output also contains the URI.

I guess #2 will only work for referenced fields. A direct call to file entity for example like `/ejson/file/{uuid}` will not render the uri value. Attaching the updated patch which handles both reference fields as well as direct call to file entity.

Thank you @subhashuyadav and @Keshav Patel.
Committed with the URL instead of the URI and some extra file data (name, size, type)