Revise validation errors

[ak88]

Changes

This will set error messages primarily for engine RPC endpoints, which is used in some hive test to test for correctness.

Format for error messages is two segments divided with ':'

• first segment is machine parseable and can be used for verification
• second part is a human readable error description Example: "InvalidAncestor: No valid ancestors could be found." "InvalidBaseFeePerGas: Does not match calculated."

This is meant to serve as a temporary solution until there is a common standard for Json RPC error codes.

What types of changes does your code introduce?

• [ ] Bugfix (a non-breaking change that fixes an issue)
• [x] New feature (a non-breaking change that adds functionality)
• [ ] Breaking change (a change that causes existing functionality not to work as expected)
• [ ] Optimization
• [ ] Refactoring
• [ ] Documentation update
• [ ] Build-related changes
• [ ] Other: Description

Testing

Requires testing

• [ ] Yes
• [ ] No

If yes, did you write tests?

• [x] Yes
• [ ] No