[BUGFIX] Re-validate changed fields only

Probably since ever, FormEngine validates the whole form when a field
changed or an IRRE item got removed. This patch introduces the following
changes:

- only fields affected by the `change` event get validated
- FormEngineValidation.validate() accepts an optional argument to define
  the container whose fields get validated. If omitted, the whole form
  is validated.

Resolves: #93046
Releases: master, 10.4
Change-Id: I48d2f597c88815ebc0374bb02cf0aed6ac4086fe
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/67094


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Richard Haeser <richard@richardhaeser.com>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Richard Haeser <richard@richardhaeser.com>