[BUGFIX] Add language flags to sys category TCA config

The sys_category TCA configuration behavior is now the same as in tt_content.
Flags and labels for the languages in the select single dropdown.

Resolves: #89607
Releases: master, 9.5
Change-Id: I5a4c2df7294b699136b62cbf4f68d2ceeae43b8e
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/62860


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Steffen Frese <steffenf14@gmail.com>
Tested-by: Sascha Rademacher <sascha.rademacher+typo3@gmail.com>
Tested-by: Daniel Goerz <daniel.goerz@posteo.de>
Reviewed-by: Steffen Frese <steffenf14@gmail.com>
Reviewed-by: Sascha Rademacher <sascha.rademacher+typo3@gmail.com>
Reviewed-by: Daniel Goerz <daniel.goerz@posteo.de>