swarm: relink typing indication

Should not be difficult

The only difficulty is that the conversation is not specified, only the message-id, so that will need some calculation or add a custom indication into:

https://tools.ietf.org/html/rfc5438#section-11

To determine:

1. where to store the convID related
2. Who store the information for read-by (daemon, or we forward the signal to client?)