[BUILDER] - Multiple builder support

[QuentinI]

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

HotShot should support multiple builders.

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

• [ ] Multiple builder support
• [ ] Tests for multiple builders

Are there any other details to include?

No response

What are the acceptance criteria to close this issue?

• Multiple builder addresses can be specified in config
• HotShot queries all builders for available blocks
• There are tests checking HotShot behaviour w.r.t builders, especially various faulty builder cases

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

No response