[TASK] Switch acceptance tests to cest format

Cest is the format recommended by codeception. It allows
more control and better abstraction.

Resolves: #73525
Releases: master
Change-Id: Icf434fd53af5653890a5174dc478d647c1bffd1c
Reviewed-on: https://review.typo3.org/46684


Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Benni Mack <benni@typo3.org>
Tested-by: Benni Mack <benni@typo3.org>