[BUGFIX] Show links to missing records in InputLink

If the linked record wasn't found (wrong uid, removed from database) we
check before trying to gather an icon for the non-existing record.

Resolves: #81804
Releases: master, 8.7
Change-Id: Ie06ec8a614650d8147f143cda8d8e6a9cb3e98e9
Reviewed-on: https://review.typo3.org/55751


Reviewed-by: Andreas Wolf <andreas.wolf@typo3.org>
Tested-by: Andreas Wolf <andreas.wolf@typo3.org>