[FEATURE] Introduce associative array keys for TCA items

The TCA types select, radio and check now have associative array keys
for their items array.

The mapping is as following:

0 => 'label' (select, radio, check)
1 => 'value' (select, radio)
2 => 'icon' (select)
3 => 'group' (select)
4 => 'description' (select; renderType=selectCheckBox)

This change eases the introduction of new functionality to the items
array in the future and provides a vastly improved code readability.

Resolves: #99739
Releases: main
Change-Id: Id0586bc8f8e1e0624eed5925be645e7b39692469
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/77626


Tested-by: Benni Mack <benni@typo3.org>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Benni Mack <benni@typo3.org>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: Markus Klein <markus.klein@typo3.org>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: Jochen <rothjochen@gmail.com>
Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Jochen <rothjochen@gmail.com>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Markus Klein <markus.klein@typo3.org>