[TASK] Add functional tests from irre_tutorial to the core

Add irre_tutorial extension as mock extension for functional tests.
Port functional tests from IRRE tutorial to the functional testing
framework and include them in the core and workspaces extensions.
Some tests are skipped for now, because the core is buggy.

Releases: 6.2
Resolves: #54812
Change-Id: I691dd97e7649c8239b6e96ce6f9a9d59e9b124c4
Reviewed-on: https://review.typo3.org/26674
Tested-by: Markus Klein
Reviewed-by: Oliver Hader
Tested-by: Oliver Hader