[DOCS] Switch form documentation to PHP-based rendering

A backport to 11.5 is not possible due to too many issues in the Docs that cannot be backported automatically.

Resolves: #103479
Releases: main, 12.4
Change-Id: Id52b3193cf270962f6d728d2dc012b5b1d5c2856
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/83585


Tested-by: Lina Wolf <112@linawolf.de>
Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Lina Wolf <112@linawolf.de>
Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Benni Mack <benni@typo3.org>