Update protocol parameters to SNARK friendly values

[jpraynaud]

Why

The current Mithril protocol parameters we use are not SNARK-friendly and need to be slightly updated. In particular, the k value is a bit too big and requires the usage of twice the number of constraints in the Halo2 circuit.
We want to create a new set of protocol parameters that is SNARK-friendly.

What

Compute new SNARK-friendly protocol parameters and deploy them to the Mithril networks

How

• Validate the new set of parameters with the cryptographers and researchers:
  • Selected parameters: k=1944, m=16948 and phi_f=0.2
  • Validate with researchers
  • Validate with cryptographers
• Rollout the protocol parameters to the Mithril networks:
  • Phase 1 (all networks must sign with the new protocol parameters before moving to next phase)
    • dev-preview
    • dev-mainnet
    • testing-preview
  • Phase 2 (all networks must sign with the new protocol parameters before moving to next phase)
    • pre-release-preview
    • release-preprod
  • Phase 3
    • release-mainnet
• Update documentation
• Add a dev blog post

[jpraynaud]

Hi @pyrros and @curiecrypt, can you confirm that we can use the above protocol parameters (k=1944, m=16948 and phi_f=0.2) for production?