[BUGFIX] EXT:form - use context specific configuration cache

Cache the EXT:form configuration depending on the YAML files which
are loaded.

Resolves: #83311
Releases: master,8.7
Change-Id: Ib612e7638f5b5ad0ddc08c17e3d3b1e645967304
Reviewed-on: https://review.typo3.org/55240


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Reviewed-by: Reiner Teubner <rteubner@me.com>
Tested-by: Reiner Teubner <rteubner@me.com>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>