LiveObject: Implement implicit attach for `objects.getRoot`

[sacOO7]

• If channel is in initialized state, objects.getRoot should implicitly attach the channel.
• If it's any other state or calling implicit attach results in any other state, then it should return relevant error.
• Implementation may be similar to Room.ensureAttached method in chat-kotlin SDK.

┆Issue is synchronized with this Jira Task by Unito