[TASK] travis-ci: Split functional tests into more parts

With the ever growing number of functional tests, we
split the suite into more parts to prevent
"No output has been received in the last 10 mins".

Change-Id: I55665c723f91f77347b376992f7a7a28da67b0fd
Resolves: #82145
Releases: master, 8.7, 7.6
Reviewed-on: https://review.typo3.org/53754


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>