[TASK] Run acceptance tests in parallel

Provide script for generating files with acceptance tests groups
to allow running them in parallel on different hosts. Very useful
for bamboo.

Usage:

Generating 5 dynamic group files:
./components/testing_framework/Resources/Core/Build/Scripts/splitAcceptanceTests.sh 5

Run tests of group 1:
./bin/codecept run Acceptance -g AcceptanceTests-Job-1 -c ...

Note group numbers start from 1, not 0.

Resolves: #79845
Releases: master
Change-Id: Ib74ec0b457ee927a906a77e648041ae15dc727d2
Reviewed-on: https://review.typo3.org/51713


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