Improvement: Prevent teachers from creating mods which datetimes (timeopen, cutoffdate, etc) collide with scheduled outages

[Menrath]

I am currently writing a small tool that does this. Feel free to see if you can add this to your auth_outage.

https://codeberg.org/linos/moodle-tool_maintenance/src/branch/main/amd/src/modedit.js

FYI: I did not use auth_outage as a base, because it has a lot of features we do not seem to need.

[Menrath]

If you would be interested in having this, I could try to find some time implementing a PR where this is can be activated optionally.