[TASK] Update backend page title

Updates the document title in backend following the brand change
from TYPO3 to TYPO3 CMS

Resolves: #53455
Releases: 6.2, 6.1, 6.0, 4.7, 4.5
Change-Id: I62782f3aa2c1dd30dc1429999e0757823ed8dbd7
Reviewed-on: https://review.typo3.org/25224
Reviewed-by: Stefan Neufeind
Tested-by: Stefan Neufeind