Implement engine_getClientVersionV1

[one-three-three-seven]

Rationale

Why should this feature exist?
The consensus client should be able to identify which execution client implementation it is using.

What are the use-cases?
To facilitate a more accurate measurement of execution layer client diversity statistics. It enables consensus clients to embed the execution client used into the graffiti.

Implementation

Do you have ideas regarding the implementation of this feature?
See https://github.com/ethereum/execution-apis/blob/main/src/engine/identification.md

Are you willing to implement this feature?
Unfortunately, it's outside my capabilities.