[MACRO] - BUILDER - Builder Interface and Simple Builder

[elliedavidson]

What is this task and why do we need to work on it?

This task adds support to HotShot for a simple Proposer-Builder Separation (PBS) protocol. We need to add this so we can support leaders interacting with builders to build blocks. Leaders may not want to build blocks themselves.

What work will need to be done to complete this task?

• [x] #2371
• [x] #2414
• [x] #2415
• [x] #2550
• [x] #2559
• [x] #2667
• [x] #3181
• [x] #3183
• [ ] #3182
• [ ] #2969
• [ ] Put a testing-only flag in the builder that randomly inserts latency or drops messages (can potentially use the unreliable network that's already implemented)

Are there any other details to include?

This will require coordination with the builder-core repository. We should have regular check-ins to ensure the above plan doesn't need to change

What are the acceptance criteria to close this issue?

• [ ] All current HoShot tests pass
• [ ] Leaders successfully handle the builder being unresponsive or slow (in this case they can propose an empty block)
• [ ] Leaders can successfully connect to an external builder
• [ ] Leaders can successfully run their own builders as a side car

Branch work will be merged to (if not the default branch)

No response