Reverb presence channels - member_added and member_removed events are not sent

[alex3493]

Pusher emits "member_added" and "member_removed" events whenever a user joins or leaves a presence channel.

However, Laravel Reverb only emit "connection" event when current user joins a presence channel. We have to fix it:

• find a workaround (listen for alternative events)
• configure reverb, so that we do get missing events (not sure)

[alex3493]

We have to check for "pusher_internal:member_added" and "pusher_internal:member_removed" events in Reverb trait InteractsWithPresenceChannels.