[TASK] Add unit tests for "outdated" extensions

Follow up with unit tests for the extended reports.

Change-Id: I097d1241722fdaf57a4a57b6d90f32359e8168f5
Resolves: #49350
Releases: 6.2, 6.1, 6.0, 4.7, 4.5
Reviewed-on: https://review.typo3.org/21646
Reviewed-by: Anja Leichsenring
Tested-by: Anja Leichsenring
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters