AbiDecode for arrays using const_generics

[xunilrj]

Description

This is part of #6860.

This completes abi encoding for arrays. Allowing arrays of any size as inputs and outputs in predicates/scripts/contracts.
This PR also allows arrays to be initialized with "const generics" such as:

#[cfg(experimental_const_generics = true)]
impl<T, const N: u64> AbiDecode for [T; N]
where
    T: AbiDecode,
{
    fn abi_decode(ref mut buffer: BufferReader) -> [T; N] {
        let first: T = buffer.decode::<T>();
        let mut array = [first; N];  // <-------------------- This can used now
        ...
        array
    }
}

Checklist

• I have linked to any relevant issues.
• I have commented my code, particularly in hard-to-understand areas.
• I have updated the documentation where relevant (API docs, the reference, and the Sway book).
  • If my change requires substantial documentation changes, I have requested support from the DevRel team
• I have added tests that prove my fix is effective or that my feature works.
• I have added (or requested a maintainer to add) the necessary Breaking* or New Feature labels where relevant.
• I have done my best to ensure that my PR adheres to the Fuel Labs Code Review Standards.
• I have requested a review from the relevant team or maintainers.

[codspeed-hq]

CodSpeed Performance Report

Merging #7008 will not alter performance

_{Comparing xunilrj/abi-decode-for-arrays (2b53ea5) with master (6cd732b)}

Summary

✅ 22 untouched benchmarks

[zees-dev]

Very useful functionality; LGTM 👍

[jjcnn]

You'll need to move the new abi_decode function to std::codec now that std and core have been merged, but otherwise it looks good.

Do we not need an implementation of AbiEncode as well?