feat(federation): Federated table sharing

[benjaminfrueh]

⚠️ Work in progress - draft PR

Federated table sharing

Allows sharing tables with users on other Nextcloud instances.

Todo

• Schema, outgoing share and frontend support 589a441
• Incoming share: create local table on receiving instance bd063c9
• Read support: fetch columns and rows from owner instance
• Write support: create, update and delete rows on remote table
• Permission propagation
• View federation
• Admin config to enable/disable tables federation
• Unit and E2E tests

🏁 Checklist

• ⛑️ Tests (unit and/or integration) are included or not needed
• 🔙 Backport requests are created or not needed: /backport to stableX.X
• 📅 Milestone is set
• 🌸 PR title is meaningful (if it should be in the changelog: is it meaningful to users?)

🤖 AI (if applicable)

• The content of this PR was partly or fully generated using AI