Ensure Schema compliance with execution-apis schema

[Nana-EC]

Problem

The relay has occasionally been shown to conform to different schema standards than other Eth client API's.
This has mostly been since not all clients observe the same standard.

Solution

Conform to the ethereum execution-apis schema

Ensure all objects and components match expected formats

Suggestions

• Ensure open rpc document added by Add an OpenRPC Document #114 matches ethereum execution-apis schema
• Run integration (not E2E) level tests against endpoints that verify schema against doc

Alternatives

No response

[ar-conmit]

There is a tool that might help running integration tests - https://github.com/open-rpc/test-coverage