[BUGFIX] Properly explode file collection uids as int

The FilesProcessor previously exploded the comma
separated list of file collection uids with trimExplode.

However, the underlying FileCollector method
expects the uids to be of type int. Therefore, the
data processor now uses GU::intExplode(), like
already done in FileContentObject, instead.

Resolves: #93193
Releases: master
Change-Id: Ib0923b1484993793e1dd50be395fac78aa61cda7
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/72204


Tested-by: core-ci <typo3@b13.com>
Tested-by: Benni Mack <benni@typo3.org>
Tested-by: Jochen <rothjochen@gmail.com>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Benni Mack <benni@typo3.org>
Reviewed-by: Jochen <rothjochen@gmail.com>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>