Implement multiple Rooms support (#27)

[evdokimovs]

Part of #27

Synopsis

Jason should be able to serve multiple Rooms with one Jason object. If Jason client joins to the many Rooms from the one Media Server, then only one WebSocket connection should serve all this Rooms.

Solution

Add authorization messages to the medea-client-api-proto. Authorize Members with this messages instead of doing it by URL with which Member connects to the Media Server.

Create wrapper around Jason's WebSocketRpcClient which will be responsible for routing and sessions management.

Checklist

• Created PR:
  • [x] In draft mode
  • [x] Name contains Draft: prefix
  • [x] Name contains issue reference
  • [x] Has k:: labels applied
  • [x] Has assignee
• [x] Documentation is updated (if required)
• [x] Tests are updated (if required)
• [x] Changes conform code style
• [x] CHANGELOG entry is added (if required)
• [x] FCM (final commit message) is posted
  • [x] and approved
• [x] Review is completed and changes are approved
• Before merge:
  • [x] Milestone is set
  • [x] PR's name and description are correct and up-to-date
  • [x] Draft: prefix is removed
  • [x] All temporary labels are removed
  • [x] e2e-demo changes are rollbacked

[evdokimovs]

FCM

Implement multiple Room support (#147, #27)

- support joining to the multiple Rooms with one Jason object in 'medea-jason' crate
- support multiple Members serving with one RPC connection in 'medea' crate
- authorize Members with protocol messages instead of URL in 'medea' crate