[BUGFIX] Use finder instance correctly

Within SiteTcaConfiguration, the $finder is now reused as much as
possible. A new clean instance is used for the individual actions.

Resolves: #87832
Releases: master, 9.5
Change-Id: I34f2d08c51042f2cfe6b4a09ac6152e0b552ab14
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/59839


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Rico Drexler <rico.drexler@gmx.de>
Tested-by: Susanne Moog <look@susi.dev>
Reviewed-by: Jörg Bösche <typo3@joergboesche.de>
Reviewed-by: Susanne Moog <look@susi.dev>