feat: add support for EIP-712 typed data

[mattsse]

Motivation

foundry-rs/foundry#2458

add support for eth_signTypedData_v4

Solution

• add TypedData type that Represents the EIP-712 typed data object
• implement encoding functions
• port various test cases from https://github.com/MetaMask/eth-sig-util/blob/main/src/sign-typed-data.test.ts
• change EIP712Domain so all fields are optional
• move some serde helpers from anvil core

PR Checklist

• Added Tests
• Added Documentation
• Updated the changelog

[mattsse]

the example in foundry-rs/foundry#2458 doesn't match hardhat's response. unsure why yet

[mattsse]

tracked down two issues:

• remove array tails when building the type hash...
• correctly encode fixedbytes

this should be good to merge, added test coverage for

• custom types
• custom arrays
• recursive types