[BUGFIX] Split functional workspaces DataHandling test execution

Travis-CI stops after 10 minutes of not having received any data,
unfortunately it seems that the execution of the whole bunch of
functional workspaces tests takes longer,
see https://travis-ci.org/TYPO3/TYPO3.CMS/jobs/20590551

The "solution" is to explicitly split up these tests for
parallel execution in Travis-CI.

Resolves: #56806
Releases: 6.2
Change-Id: Ib5e67e6793adb9d7896ce89872ccfa080ca849bd