feat(code/consensus): Add support for full nodes

[romac]

Background

All nodes have a validator key. A validator node is a node that has its validator key included in the "current" validator set.

A validator node signs and broadcasts consensus messages. Every node gossip consensus messages. Every processes sends and receives consensus control/gossip messages.

Validator nodes may have a more restrictive network setup. But this is not mandatory.

So, being a validator is not a characteristic, it is a property. A node can be a validator in height H but not in height H + 1. This is application dependent.

All nodes process messages in the same way. But when producing a message, a node whose validator key is not in the current validator set implements a noop. An active validator sign the message and "broadcast" it.

by @cason

Implementation

Change the logic in malachitebft-consensus to not emit Sign* and Publish* effects when we are not in the validator set.

Testing

Update the test framework so that we can mark some nodes as not being part of the validator set (turning them into full nodes) ideally with a nice fluent API, e.g.:

let mut test = TestBuilder::<()>::new();

// validator node (in validator set, voting power 1 by default)
test.add_node().start().wait_until(5).success();

// validator node (in validator set, voting power 5)
test.add_node().with_voting_power(5).start().wait_until(5).success();

// full node (not in validator set)
test.add_node().full_node().start().wait_until(5).success();

test.build().run(Duration::from_secs(30)).await

[hoank101]

hi, i can do it, please asign to me

[romac]

Awesome, thank you! 🙌