[TASK] Add namespaing to ConfigurationManagerInterface

Resolves: #47201
Releases: 6.0, 6.1
Change-Id: I5098a63e9cad8848e2c14da9d9e99de6885d45e9
Reviewed-on: https://review.typo3.org/19951
Reviewed-by: Thomas Maroschik
Tested-by: Thomas Maroschik
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters