Implement missing RTP2f

[sacOO7]

• Fix missing RTP2f same as - Fix missing RTP2f same as ably/ably-cocoa@1d2f015 and https://github.com/ably/ably-cocoa/pull/1891/files

┆Issue is synchronized with this Jira Task by Unito

[sacOO7]

Presence queue was added as a part of the commit c41ddeb. This means there is no need to maintain channel queue as per spec. It can be completely removed altogether. This has been identified while working on ably-ruby. See comment -> ably/ably-ruby#407 (comment)

Note - As per

ably-go/ably/realtime_channel.go

Line 272 in dd8236f

func (c *RealtimeChannel) onConnStateChange(change ConnectionStateChange) {

, for both ConnectionStateConnected and ConnectionStateFailed, we need to flush and fail the presence queue as well.
We used to do it before this commit was added. Currently, we only do it when channel is detached, failed or suspended. Also, need to check if this is really needed