Tuple/Struct support #73

[jcarraror]

TODOs:

• Check Tuple encoding correctness
• ABI Json support for tuples
• Decide how the reflection interface will use the new Decoder
• Tuple/Struct encoding support
• Tuple/Struct decoding support
• ABI Refactor to stop using variant as data collector

[itamarcps]

Adding tuple support required us to shift both the ABI and ContractReflectionInterface entirely to a pure template-based approach. This effort, particularly integrating nested tuple/struct support, was more challenging and time-consuming than anticipated, necessitating a complete overhaul of the existing system.

Highlights:

• The compiler now autonomously generates functions for encoding/decoding types, applicable for each function call, supporting all basic Solidity types.
• Elimination of dependency on the "meta" metaprogramming library.
• Capability to return nested tuples and vectors, with compiler-generated code for these structures.

Implementation Example:
See SimpleContract.cpp for examples of the new ABI's application, demonstrating the enhanced handling of std::vector<T>P and std::tuple<T...>.

Impact:
The refactor has affected all areas interacting with the ABI, particularly in DynamicContracts function registrations and JSON ABI generation. New tests have been added to ensure the integrity of these changes.

Notable Changes:

• Deprecated ABI::Encode::encodeFunction; transition to ABI::FunctorEncode.
• Removed ABI::Types, BaseTypes, and BytesEncoded as the templated ABI negates their necessity.
• DynamicContract no longer uses std::any, reflecting the new templated methodology.
• Removed specializations for decoding/encoding std::vector<BaseSolidityType> since the templated functions handles std::vector<T>.

Next Steps:

• Remove std::any usage within the ContractFactory.