Commit boost API - Generate Proxy Key, Signing Request

[usmansaleem]

PR Description

Commit boost API - Generate Proxy Key, Request Signature. Implementation of https://commit-boost.github.io/commit-boost-client/api

• Routes and Handler for Generate Proxy Key CommitBoostGenerateProxyKeyHandler, CommitBoostGenerateProxyKeyRoute
• Custom SSZ classes for calculating signing roots (BLSProxyDelegation, SECPProxyDelegation,ProxyDelegation)
• Create BLS and/or SECP proxy keys (utility classes ProxyKeyGenerator and SigningRootGenerator)
• Unit/Acceptance tests

Other changes:

• Renamed DepositSigningRootUtil to Web3SignerSigningRootUtil
• Refactored EthPublicKeyUtils to use Bouncycastle libraries to handle SECP Keys.
• Introduced CommitBoostParameters interface and PicoCommitBoostApiParameters implementation
• Use ZERO genesis validators root for commit boost API. However, added additional code to use actual GVR if Commit Boost client changes its implementation in future.
• Updated Eth2Subcommand. Moved network overrides cli options to mixin class PicoCliNetworkOverrides
• Updated Eth2Runner and register CommitBoostGenerateProxyKeyRoute
• Updated SECP bulkloader to handle compressed public keys as identifiers
• Updated DefaultArtifactProvider to add proxy signers. Refactored the code to make it a bit cleaner

Fixed Issue(s)

See #1017

Documentation

• I thought about documentation and added the doc-change-required label to this PR if updates are required.

Changelog

• I thought about adding a changelog entry, and added one if I deemed necessary.

Testing

• I thought about testing these changes in a realistic/non-local environment.

[usmansaleem]

@jframe this monstrous PR is ready for review, give it a go at your convenience :)

[jframe]

@jframe this monstrous PR is ready for review, give it a go at your convenience :)

Is there anyway to break this PR into smaller PRs? It's quite big to review at the moment

[usmansaleem]

Closing as PR was too long.