feat: Add out-of-office message API

[ChristophWurst]

• Resolves: Out-of-office: Expose data via OCP/OCS APIs #40650

Summary

tbd

TODO

• Emit events
• Coordinator implementation
• OCS endpoint(s)
• Caching layer

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)

[ChristophWurst]

• We will also need an OutOfOfficeClearedEvent next to OutOfOfficeScheduledEvent and OutOfOfficeChangedEvent.

[ChristophWurst]

Events are emitted. Anything else missing?

[ChristophWurst]

The events part is definitely done and working. Tested with #41340 :)

[ChristophWurst]

Let's get this in

[provokateurin]

OpenAPI looks good

[st3iny]

Nope, but now it works. There was a casing issue in ResponseDefinitions.

Thanks for taking care of the cleared event.

Unfortunately, OutOfOfficeStartedEvent and OutOfOfficeEndedEvent are not emitted yet. I have a very crude version locally that has some problems.

I can push it if required. IIRC, we might need it for the autoresponder in Mail.

[ChristophWurst]

Right. I only looked at the CRUD events, not the time related once.

We can also split the PR into the bits that already work and deliver the rest later

[st3iny]

Unfinished events are gone and we are good now.

[ChristophWurst]

👍 for the latest pushes