[TASK] Add first functional tests for DataHandler

The patch introduces some common database fixtures that can be
re-used between tests. Two base functional tests in core
data handler are activated and another one in workspace.

Functional test xml is changed to execute all core and workspace
tests. Most of them are not working yet and marked as incomplete
for new.

Resolves: #51151
Releases: 6.2
Change-Id: Ic8e3da4f1064689e6ea7ef2365b0f8b1a3ce91f4
Reviewed-on: https://review.typo3.org/23171
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn
Reviewed-by: Tymoteusz Motylewski
Tested-by: Tymoteusz Motylewski
Reviewed-by: Anja Leichsenring
Tested-by: Anja Leichsenring
Reviewed-by: Stefan Neufeind
Tested-by: Stefan Neufeind