- Implement new `process_execution_payload` (as `process_execution_payload_envelope`).
- Implement new processing for deposit requests, including logic for adding new builders to the registry with index reuse.
- Enable a bunch more operations EF tests (most of them except bid processing/payload attestations/etc which we don't have code for yet).
Co-Authored-By: Michael Sproul <michael@sigmaprime.io>