[TASK] Move CSV fixtures handling to FunctionalTestCase

Usage of CSV fixtures is now possible for all functional tests.
Previously it was available only for DataHandler tests.
This patch is backward compatible.

Resolves: #80007
Releases: master, 7.6
Change-Id: I6aa69825ac144b8c955b51a61060a822163511ca
Reviewed-on: https://review.typo3.org/51838


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>