[TASK] Simplify FAL related unit tests

To finally tame the FAL related unit tests,
the resource related BaseTestCase is dissolved
and merged into consuming classes as first step.
This simplifies the construct and allows further
refactorings.

Resolves: #98936
Releases: main
Change-Id: Id8da6b47a5d16d7eb38bfecf91d41d9365d4df7d
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/76299


Tested-by: core-ci <typo3@b13.com>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Tested-by: Oliver Klee <typo3-coding@oliverklee.de>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>