[TASK] Add form framework RequiredValidatorEditor test

Resolves: #85673
Related: #85608
Releases: master, 8.7
Change-Id: If351dd316c628450e09e579d0cccbe7a7cefe213
Reviewed-on: https://review.typo3.org/57712


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Susanne Moog <susanne.moog@typo3.org>
Tested-by: Susanne Moog <susanne.moog@typo3.org>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>