eip712 breaking change

[fubuloubu]

Hey all! Found your package among my dependents. There is a small breaking change update in eip712 v0.3.0 that is going to require you to update some of the stuff in here: https://github.com/InjectiveLabs/sdk-python/blob/master/pyinjective/orderhash.py

See the docs for an example of how to update:
https://docs.apeworx.io/eip712/stable/userguides/quickstart.html#quick-usage