[BUGFIX] Re-enable caching and centralize UserTSconfig in BE_USER

In order to continue sorting out various places when UserTSconfig
should be used, and how to properly use caching and condition
matching, compiling of UserTSconfig is now centralized into one method.

In addition, this patch actually now caches the UserTSconfig
again, in the "hash" cache, which wasn't the case before in v10.0+.

Resolves: #89755
Releases: master
Change-Id: Icf6e8d7a199fb234336b4bd557627d254ff4e6e3
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/62419


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Susanne Moog <look@susi.dev>
Reviewed-by: Markus Klein <markus.klein@typo3.org>
Reviewed-by: Susanne Moog <look@susi.dev>