conversation: follow daemon changes for sending status

cf jami-docs/developer/delivery-status
+ Basically this patch uses the new SwarmMessage.status to show
current interaction status.
+ setRead only updates the status if the interaction is newer (else,
because signal are not guaranteed to be ordered, this can cause the
lastDisplayed_ to be incorrect).
+ Some old code is removed and unused signal
+ MessageReceived updates status if needed

GitLab: #1487
Change-Id: I4d4d5dce8dc12ab638e89e3f8431810b29a72087