feat: SHA2 partial precompile

[ivokub]

Description

This PR adds dedicated precompile circuit for SHA256 permutation on 16-bit limbs (as provided by zkEVM). Keeping in draft until final interface is determined.

Related #466 and #576

Type of change

• [x] New feature (non-breaking change which adds functionality)

How has this been tested?

• [x] TestSHA256Permutation for fixed inputs

How has this been benchmarked?

Checklist:

• [x] I have performed a self-review of my code
• [x] I have commented my code, particularly in hard-to-understand areas
• [x] I have made corresponding changes to the documentation
• [x] I have added tests that prove my fix is effective or that my feature works
• [x] I did not modify files generated from templates
• [x] golangci-lint does not output errors locally
• [x] New and existing unit tests pass locally with my changes
• [x] Any dependent changes have been merged and published in downstream modules

[ivokub]

cc @Tabaie - a mental note to myself, that maybe I can reuse some utility functions from compression circuits for changing the endianness of the inputs.

[ivokub]

Closing this PR. Linea prover calls the SHA2 permutation itself now and this wrapper is not needed.