Support mev-boost in lighthouse

[come-maiz]

Here we track the support of mev-boost in lighthouse.

✔️ Builder API
❓ local fallback when builder not available
✔️ local profit comparison
✔️ circuit breaker

https://lighthouse-book.sigmaprime.io/builders.html
Guide to testing the unstable integration: https://mirror.xyz/ladislaus.eth/ah5UOhcstfmnk5rzTBQ-e26XudUqmxr3flnkLqlEDYE

[come-maiz]

@realbigsean is the human writing the code for mev-boost in lighthouse.

Issues in the lightclient repository

• MEV Boost compatibility sigp/lighthouse#2987
• Builder API Tracking sigp/lighthouse#3091

Merged work

• [Merged by Bors] - Kiln mev boost sigp/lighthouse#3062
• [Merged by Bors] - Builder Specs v0.2.0 sigp/lighthouse#3134
• [Merged by Bors] - Register validator api sigp/lighthouse#3194
• [Merged by Bors] - Remove builder redundancy sigp/lighthouse#3294
• [Merged by Bors] - Strict fee recipient sigp/lighthouse#3363
• [Merged by Bors] - Update invalid head tests sigp/lighthouse#3400
• [Merged by Bors] - Don't use the builder network if the head is optimistic sigp/lighthouse#3412
• [Merged by Bors] - don't register exited or slashed validators with the builder api sigp/lighthouse#3473
• [Merged by Bors] - Validator registration request failures do not cause us to mark BNs offline sigp/lighthouse#3488
• [Merged by Bors] - Builder profit threshold flag sigp/lighthouse#3534

[paulhauner]

The latest Lighthouse release contains v0.2.0 builder API support 🎉

https://github.com/sigp/lighthouse/releases/tag/v2.5.0