feat: add gravity nonce

[byte-bandit]

Related Github tickets

• [Compass] Add gravity nonce VolumeFi/paloma#1620

Background

Gravity expects atomically incrementing nonces with every event emitted. At the moment, that's not the case, as the emitted event_id is shared across different message types. The gravity implementation is a lot more strict that our regular communication channels as in it will enforce a id = id + 1 constraint for every nonce it receives, and will attest to them in order only. This is to ensure correctness of order of funds transferred.

This change will also require an update to Pigeon and possibly Paloma in order to populate the constructor properly.

[byte-bandit]

@webelf101 I have no idea how to get the tests running for this, I've updated conftest.py but looks like that alone wasn't enough.

[webelf101]

LGTM. The test was built using brownie framework but it isn't updated anymore so the test will fail. We may need to rebuild tests using apeworx.