[TASK] CGL cleanup

Cleanup the namespaced classes for some CGL stuff.

Resolves: #55060
Releases: 0.6
Change-Id: I486ce7631611bfb6a6fcdcd15c3822595154f3a7
Reviewed-on: https://review.typo3.org/26886
Reviewed-by: Francois Suter
Tested-by: Francois Suter