[TASK] Change extension category to service

Change-Id: I059dd42c3bba8a45565b09b43f2268cafbe4e2d2
Releases: 1.1.0
Fixes: #52120
Reviewed-on: https://review.typo3.org/23894
Reviewed-by: Fabien Udriot
Tested-by: Fabien Udriot