[TASK] Use namespaces classes

Followup to commit df04ae1

Resolves: #57381
Change-Id: I92894f2c0c6663a52d9fca4e9ad0b8b3c4de01d0
Reviewed-on: https://review.typo3.org/28913
Reviewed-by: Georg Ringer
Tested-by: Georg Ringer