Add Icicle GPU acceleration to Plonk BN254 Prover

[bigsky77]

Description

This PR adds experimental support for Icicle GPU acceleration library for Plonk backend and the BN254 curve.

Type of change

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

How has this been tested?

[X] Using the circuits in gnark/examples/plonk/main.go

1. Follow the instructions for setting up Icicle in the linked fork above
2. From gnark run go run examples/plonk/main.go

[X] Using Ingonyama's fork of Succinct Lab's Gnark-Plonky2-Verifier

1. From Gnark-Plonky2-Verifier run go run benchmarks.go --icicle

How has this been benchmarked?

Benchmarks ran on Gnark-Plonky2-Verifier using AWS: g5.8xlarge A10g 32 core 128GB.

Benchmarks can be seen here.

Dependencies

This merge requests depends on modifications to the following two repositories.

1. IcicleGnark - Pull Request
2. Gnark-Crypto - Branch

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
• Any dependent changes have been merged and published in downstream modules