[TASK] Move StorageRepositoryTest tests to AbstractRepositoryTest

All tests in the class belong to AbstractRepository, so the tests move.

Change-Id: I5e78e0d61a2d8f8bcfd06d871a909b749417e616
Resolves: #51923
Releases: 6.2, 6.1, 6.0
Reviewed-on: https://review.typo3.org/23766
Reviewed-by: Helmut Hummel
Tested-by: Helmut Hummel