[TASK] Extract symmetric mn scenario from ext:irre_tutorial

The scenario provided by tables tx_irretutorial_mn_sym_* gets
its own test extension and gets loaded where needed.

Resolves: #96445
Releases: main, 11.5
Change-Id: I55a9c3ba1a5e1d238279a641f4e5380d936c23c9
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/72821


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