Rollout own ABI coder: implement all basic decoders

[mconnelly8]

Feature

• own performant abi coder with good error handling

Some design choices previously chosen:

• use uint8array everywhere to avoid 0x prefixes nightmare and to make it more performant
• detailed error handling to enable user to locate error

Task:

• [ ] implement all basic decoders

Tasks started atfeat/abi-coder (it was old branch that got rebased so some stuff is not aligned). Marin plans to work on it in his own time, but can split tasks.

[mconnelly8]

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