Feat/poseidon2

[ThomasPiellard]

Description

Implementation of poseidon2 for t=2,3 following reference implementation reference paper TBD: algos 1, 2, 3 of https://tosc.iacr.org/index.php/ToSC/article/view/8913/8489 for finding internal matrices when t>3

Type of change

Please delete options that are not relevant.

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] This change requires a documentation update

How has this been benchmarked?

Please describe the benchmarks that you ran to verify your changes.

• [x] Benchmark A, on Macbook pro M1, 32GB RAM

goarch: amd64 pkg: github.com/consensys/gnark-crypto/ecc/bn254/fr/poseidon2 cpu: Intel(R) Core(TM) i7-8750H CPU @ 2.20GHz BenchmarkPoseidon2-12 163784 7035 ns/op

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