Off-chain communication via libp2p

• Do a first pass that communicates via messages on CED and/or the fastest test blockchain we support.
• Backend support and CLI to ensure the go-libp2p-daemon and/or JS library is started with the correct parameters
• Backend support and CLI to send and receive messages between two ETH addresses
• Backend support and CLI to queue, dequeue for active addresses with append-only DB schema
• Backend support and CLI to filter before queuing or select before dequeuing messages for active addresses
• Have a "negotiation" and/or "shopping" UI for negotiating contract terms
• Actually use libp2p for off-chain communication.