feat(signaling): Don't send all room userids in signaling server requests

[fancycode]

☑️ Resolves

• Fix Remove alluserids and similar lists from the signaling messages #13815

🛠️ API Checklist

🚧 Tasks

• Requires Don't need all users in requests from Talk strukturag/nextcloud-spreed-signaling#1175
• The signaling server should add a new feature id so Talk can check if a supported version is running.
• Check all clients that receiving events based on the modified requests can also contain just the changed/affected user ids. Currently the signaling server constructs the full lists for the signaling messages internally.

🏁 Checklist

• ⛑️ Tests (unit and/or integration) are included or not possible
• 📘 API documentation in docs/ has been updated or is not required
• 🔖 Capability is added or not needed

[nickvergessen]

Requires strukturag/nextcloud-spreed-signaling#1175

What's the exact merge order? I assume:

• Make sure all mobile apps and web don't use it
• Drop in HPB
• Drop in Talk

[fancycode]

What's the exact merge order? I assume:

• Make sure all mobile apps and web don't use it

Yes, that must be checked first.

• Drop in HPB
• Drop in Talk

Here the order doesn't really matter. If the whole user lists are no longer sent by Talk, the HPB will not forward them / skip some notifications (see strukturag/nextcloud-spreed-signaling#1175 (comment)).

If the HPB doesn't parse them, it will only send the changed ones / skip some notifications.