[BUGFIX] Show form definitions with same filename from different storages

If multiple storages for form definitions exist and two or more storages
have form definitions with the same filename, the latter form definition
would not be shown in the list of the form manager.

The patch fixes this problem.

Resolves: #88539
Releases: master, 9.5
Change-Id: Ifd39a0ba079e7f6bc9a1f800fc63696f4085dbc7
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/61891


Tested-by: Susanne Moog <look@susi.dev>
Tested-by: Björn Jacob <bjoern.jacob@tritum.de>
Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Ralf Zimmermann <ralf.zimmermann@tritum.de>
Reviewed-by: Susanne Moog <look@susi.dev>
Reviewed-by: Björn Jacob <bjoern.jacob@tritum.de>
Reviewed-by: Ralf Zimmermann <ralf.zimmermann@tritum.de>