[TASK] Rename postProcessingMatcher slot to be "FilePermissionsAspect"

Change-Id: I7750cc7a7c60af342cf227a370809e1347066ee4
Resolves: #59331
Releases: 3.0.0
Reviewed-on: https://review.typo3.org/30553
Reviewed-by: Fabien Udriot
Tested-by: Fabien Udriot