[TASK] Switch from xml imports to csv in acceptance tests

The acceptance test base class in testing-framework
now allows to load .csv instead of .xml files to
prime the database with records.

These files are easier to read and maintain and we
avoid a fixture dependency to the testing-framework
this way.

$ composer req --dev typo3/testing-framework:dev-main

Change-Id: I7055215a2006d985af1b19929157bdef2190854d
Resolves: #97921
Related: #96856
Releases: main
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/75156


Tested-by: Benni Mack <benni@typo3.org>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Benni Mack <benni@typo3.org>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>