[TASK] Adjust the way TCA is overridden

Follow example of EXT:sys_file_metadata

Change-Id: I4bf19951eab5fb6bfac7c84c41138830bd519e28
Releases: 3.0
Resolves: #59052
Reviewed-on: https://review.typo3.org/30352
Reviewed-by: Fabien Udriot
Tested-by: Fabien Udriot