[TASK] Simplify fetching section labels in global settings

Put labels into the configuration description file
to have everything in one place.

With that in place, we can put the description directly
into the configuration data that is prepared for the edit view.

If we do so, we can get rid of the view helper
and one method in the configuration service which only
returned the labels.

Resolves: #84938
Releases: master
Change-Id: I12e5cf1ce3873d41789a52e41e6bac87da86cf9e
Reviewed-on: https://review.typo3.org/56876


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Benni Mack <benni@typo3.org>
Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>