Use arrays for batched CurlP

[pvdrz]

Description of change

Add a BcTritArr<N> struct akin to [u8; N] to avoid heap allocations and dereferences while hashing.

This improves performance from 3 to 5% according to the benchmarks.

Type of change

Choose a type of change, and delete any options that are not relevant.

• Enhancement (a non-breaking change which adds functionality)

How the change has been tested

Using the existing test and benchmark suite

Change checklist

Tick the boxes that are relevant to your changes, and delete any items that are not.

• I have followed the contribution guidelines for this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• I have checked that new and existing unit tests pass locally with my changes
• I have updated the CHANGELOG.md, if my changes are significant enough