[TASK] Remove unsuitable searchFields from sys_file_reference

This removes some searchFields from sys_file_reference, since they
are not suitable for users, searching for such records in the backend.

As a side effect, a superfluous condition in workspaces is removed.

Resolves: #93634
Releases: master
Change-Id: I5204a79146128cbca0a3b74eda7b11ed5bcd7119
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/68171


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Benni Mack <benni@typo3.org>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Benni Mack <benni@typo3.org>
Reviewed-by: Stephan Großberndt <stephan.grossberndt@typo3.org>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>