There were a couple of issues on how we handle pinned messages:
1) Clock of the message was only checked when saving, meaning that the
client would receive potentially updates that were not to be
processed.
2) We relied on the client to generate a notification for a pinned
message by sending a normal message through the wire. This PR changes
the behavior so that the notification is generated locally, either on
response to a network event or client event.
3) When deleting a message, we pull all the replies/pinned notifications
and send them over to the client so they know that those messages
needs updating.
* add PinMessage and PinnedMessage
* fix gruop pin messages
* add SkipGroupMessageWrap to pin messages
* update pinMessage ID generation to be symmetric
Andrea Maria Piana
Igor Sirotin
Samuel Hawksby-Robinson
Vitaliy Vlasov
Andrea Franz