538: Add ping protocol to ensure connection is alive r=da-kami a=da-kami
Fixes#532
Adds the ping behaviour to both ASB and CLI behaviour that periodically pings a connected party to ensure that the underlying network connection is still alive.
This fixes problems with long-running connections that become dead without a connection closure being reported back to the swarm.
Co-authored-by: Daniel Karzel <daniel@comit.network>