Commit-Boost integration

[mempirate]

Context

We'd like to support running Bolt as a commit-boost module. For Bolt, this means 2 things:

• If run with commit-boost, signatures should be requested from commit-boost. There are 2 types of signatures: BLS for authentication (what constraints should be signed with), and ECDSA for binding commitments. commit-boost has an open issue for ECDSA: feat(signer): add ECDSA proxy keys Commit-Boost/commit-boost-client#87. We can provide a flag for --signer-api which would indicate to the process that it is running alongside commit-boost.
• We also need to modify the regular PBS module to support the constraints-API. An example can be found here: https://github.com/eserilev/il-boost

Commit-boost documentation: https://commit-boost.github.io/commit-boost-client

[mempirate]

Closing this as the final touches will be added when testing the whole flow.