Tracking issue for using zenoh in dora

[phil-opp]

Dora currently uses custom TCP streams to communicate with remote nodes (related: #459). This only works if the machines have public IPs, which is often not the case for cloud instances. By using zenoh, we could make it easier to deploy to cloud systems.

Other possible advantages of using zenoh:

• Simplify metadata communication between nodes and the daemon.
  • We want to continue using shared memory for message data to benefit from zero-copy (especially relevant for large messages).
  • However, we could use zenoh to send small metadata, such as drop tokens or log messages.