[WIP] Maintenance Mode Endpoint

[ferishili]

This issue is related to this [WIP] PR in Opencast: opencast/opencast#6084
The implementation should begin right after getting merged in opencast.

[ferishili]

[UPDATE]: As of 12.03.2025, despite our efforts to pursue and encourage everyone involved in the main pull request in Opencast, no further progress has been made. Therefore, we need to postpone this issue to the next release of the library.