Add E2E tests for Control API

[evdokimovs]

Requires #178, #179

Synopsis

This PR implements E2E tests for Control API's.

Solution

• [x] Endpoint creation
• [x] OnJoin callbacks
• [x] OnLeave callbacks

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

[evdokimovs]

FCM

Add E2E tests for Control API (#180)

Additionally:
- fix race that caused emitting PeerCreated event for Peer that has not been fully initialized 
- fix race that caused RpcConnectionClosed message not being sent to Room