Port ethabi json tests

[mouseless0x]

Motivation

Port the JSON tests from ethabi to evaluate the json-abi crate in Alloy. (Addresses #103)

Solution

Tests ported over from ethabi:

• ethabi/src/contract.rs to test Alloy's JsonAbi type
• ethabi/src/event_param.rs to test Alloy's EventParam type
• ethabi/src/state_mutability.rs to test Alloy's StateMutability type
• ethabi/src/operation.rs to test Alloy's AbiItem type
• ethabi/src/param.rs to test Alloy's Param type

PR Checklist

• Added Tests
• Added Documentation
• Breaking changes

[DaniPopes]

This is great, just a nit

[mouseless0x]

commented out sanitize tests have been removed

[DaniPopes]

Thanks!