MINOR: peers: Separate id of update messages from the update tree

MINOR: peers: Separate id of update messages from the update tree

Now the updates are no longer tracked by stick-table and we are no longer
use their id to detect missed updates, there is no reason to have a matching
between the internal update id in the id used in updated messages.

So, now, for a given peer, id of the last update messages sent is saved in
each shared table and it is incremented when a new message is updated.