[TASK] Extend Regular DataHandler functional tests

* add third tt_content element with localization in live context
* add new tt_content delete placeholder in different workspace
* populate changes to all scenarios in live and workspace context

Releases: 6.2, 6.3
Resolves: #59881
Change-Id: I644e264048a5c33c0a613d5f8440975cabd40721
Reviewed-on: https://review.typo3.org/31588
Reviewed-by: Oliver Hader
Tested-by: Oliver Hader