Implement basic test framework for consensus

[abailly]

Goal

Implement model-based testing framework that's able to compare the result of testing "any" implementation of Cardano consensus that can be connected to through node-to-node protocols.
The main goal is to scaffold the whole machinery required to run a validating node, of course without the full validation

Definition of done

Demonstrate we can run same test model against Haskell consensus and Amaru consensus, and compare the results.

• Network is faked (eg, no real connection is made
• Only the chain's headers are validated
• There's only one upstream and downstream node

Basic scenario

1. Start "node" from scratch
2. connect to a fake upstream node using ChainSync protocol and have a downstream node connected using ChainSync protocol
3. fake upstream will update node through a random walk of a pre-generated chain
4. fake downstream will receive the same information

Failure modes

The synchronising node should reject adversarial upstream and downstream peers:

• Generate invalide headers => node should disconnect from upstream peer
• Generate incorrect messages not respecting the protocol => node should disconnect from upstream and downstream peer

[abailly]

@KtorZ I have updated the issue to reflect today's discussion