[FEATURE] Backport ClassNamingUtility

ClassNamingUtility is useful since the introduction of namespaces
in 6.0. Originally this feature was introduced with 6.1.

Change-Id: I7ccc2a25e60c5deda36cdce0c3eaab213101ab49
Resolves: #50756
Releases: 6.0
Reviewed-on: https://review.typo3.org/22795
Reviewed-by: Anja Leichsenring
Tested-by: Anja Leichsenring
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn