This PR separates ENGINE from Ethbackend. It makes it so:
1) EthBackend not a god class
2) We can abstract away engine API so that we can make it CL-like and
enable Consensus-Execution driven design
3) Objective is Json-RPC -> Engine Consensus Module -> Execution module.
- breaks dependency from staged_sync to package with block_reader
implementation
- breaks dependency from snap_sync to package with block_reader
implementation
- breaks dependency from mining to txpool implementation
Passing consensus-specs tests for Capella. Processing of withdrawals and
ExecutionChanges. efficient non-validation implemented. Refactored:
ExecutionPayload/ExecutionPayloadHeader.
