[BUGFIX] Ensure online media without author works

When an oembed provider does not send
an "author_name" property, then the request fails,
and there is a sys_file without a sys_file_metadata.

This then results that the show info popup does not work.

Resolves: #101877
Releases: main, 12.4, 11.5
Change-Id: If6ead0084664372b9133fdd544ede90aa8a0e5d7
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/80903


Reviewed-by: Benjamin Franzke <ben@bnf.dev>
Tested-by: Benjamin Franzke <ben@bnf.dev>
Tested-by: core-ci <typo3@b13.com>