Bring presence signatures in line with spec (add `extras` argument)

[lawrence-forooghian]

The spec says that RealtimePresence’s enter*, update* and leave* methods are meant to accept an optional extras argument. We do not support this. To pass extras, you need to pass a PresenceMessage instance. We should consider bringing these APIs in line with the spec.

┆Issue is synchronized with this Jira Task by Unito

[sync-by-unito[bot]]

➤ Automation for Jira commented:

The link to the corresponding Jira issue is https://ably.atlassian.net/browse/SDK-3911