feat: Add OCM discovery and requests events.

[redblom]

Feature

Add OCM discovery and endpoint requests events and API documentation.

OCP\OCM\Events\LocalOCMDiscoveryEvent
OCP\OCM\Events\OCMEndpointRequestEvent

See nextcloud/server#57853

🖼️ Screenshots

✅ Checklist

• [ x] I have built the documentation locally and reviewed the output
• [ x] Screenshots are included for visual changes
• [ x] I have not moved or renamed pages (or added a redirect if I did)
• [ x] I have run codespell or similar and addressed any spelling issues

[redblom]

Note: pending backport to stable33 of nextcloud/server#57853

[skjnldsv]

@redblom please ping the dev/reviewers when the server PR is merged :)

[github-actions]

Hello there,
Thank you so much for taking the time and effort to create a pull request to our Nextcloud project.

We hope that the review process is going smooth and is helpful for you. We want to ensure your pull request is reviewed to your satisfaction. If you have a moment, our community management team would very much appreciate your feedback on your experience with this PR review process.

Your feedback is valuable to us as we continuously strive to improve our community developer experience. Please take a moment to complete our short survey by clicking on the following link: https://cloud.nextcloud.com/apps/forms/s/i9Ago4EQRZ7TWxjfmeEpPkf6

Thank you for contributing to Nextcloud and we hope to hear from you soon!

(If you believe you should not receive this message, you can add yourself to the blocklist.)