[BUGFIX] Correct workspace overlays in DataMapProcessor

Scenario:
* Create a live page that has a 'media' resource
* Create a localization of that page
* Go to workspace
* Edit the localized page
* Save
* Save again
-> crash "Array to string conversion" in DataHandler
   isSubmittedValueEqualToStoredValue()

Investigating this, the issue is not in
isSubmittedValueEqualToStoredValue() itself, but
within DataMapProcessor, which fails to apply
a workspace overlay due to #92209: The default
WorkspaceRestriction is not sufficient in this case.

The patch changes DataMapProcessor to apply
workspace overlays in a different way for this
special case.

Resolves: #97989
Related: #92209
Releases: main, 11.5
Change-Id: I176aa2d2e209224b48517b872ea39b1e01f06af7
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/75272


Tested-by: core-ci <typo3@b13.com>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>