refactor!: replace string types with force-validated pydantic types

[bitwise-constructs]

What I did

All the types used in EIP712 contracts are now using Pydantic annotated types with built-in validation

fixes: #22 Fixes: APE-1782

How I did it

This PR is being developed in coordination with an overhaul of the eth_pydantic_types library here: https://github.com/ApeWorX/eth-pydantic-types/pull/11

How to verify it

Checklist

• [ ] All changes are completed
• [ ] New test cases have been added
• [x] Documentation has been updated

[bitwise-constructs]

@antazoey 2 tests are broken but will be good to talk about tomorrow and get into how heavy to enforce the pydantic types

[antazoey]

it's comin' along!