Allow creating and using Structs defined in contract ABI

[fubuloubu]

Overview

Some contracts define custom structs. It would be helpful to be able to use those definitions directly

Specification

s = contract.MyStruct(a1, a2, ...)  # Initialize a struct

assert contract.myStruct() == contract.MyStruct(a1, a2)  # comparisons for Assertions

s.encode(packed=True)  # encode a struct to bytes (unpacked by default)
s = contract.MyStruct.decode(data_bytes, packed=True)  # decode a struct from some bytes

Dependencies

This feature is already available on abi encoding and decoding for methods, so it's a matter of exposing it more formally as something you can use directly from the contracts ABI

[linear]

APE-1699 Allow creating and using Structs defined in contract ABI