Implement echo connection check #1647
Description
Background
While we haven't concluded the investigation in #1206 because it is difficult to replicate this state, it is evident that implementing an echo/ping-pong check would remove the possibility of the network ending up in these states.
What is an echo check? It's a check where one node sends a message (just an incremental ID is sufficient) to another node, and the other node echos this message back to the first node. When the node receives the echo message, it knows the connection is up in both directions and can also measure the network latency/round-trip time as a bonus.
User Story
As a node operator I'd like my node to be able to notice if loses it's connection with a peer.
Acceptance Criteria
MPC nodes uses a ping-pong protocol to determine if their peers are up or not.
Resources & Additional Notes
No response