[TASK] Unify DataHandler test structure

Resolves: #58868
Releases: 6.2
Change-Id: I0f5aeb1d211e542cb323fba11b07a0b8be7d3ed0
Reviewed-on: https://review.typo3.org/30175
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn
Merge remote-tracking branch 'upstream/master'
[TASK] Extend DataHandler IRRE functional tests

Extend CSV and ForeignField test with
* copyParentContentToDifferentPage
* modifyHotelChild

Resolves: #58854
Releases: 6.2
Change-Id: Iba332ccee1728bf1e28ff5719029b6ab73a30c53