[BUGFIX] Allow CSH details for extbase based FlexForms

In case of extbase many FlexForm fields are called
settings.*. As "settings" is part of the field it
should not be removed as extra identifier.

Resolves: #80295
Releases: master,9.5
Change-Id: I206f28cfc360cb526f488b2fb016139246c2cad8
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/63003


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Benni Mack <benni@typo3.org>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Benni Mack <benni@typo3.org>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>