Rpc error handling

[RazorClient]

This pr introduces the Result[Opt[T], string] semantics to the rpc layer that allows us to handle the case where we need to differentiate between

• err(...)
• ok(none(...))
• ok(some(...))
  also adds the tail semantics from the pruner to "earliest" tag resolution

address reviews

• FIx:minor fixes to receipt rpc endpoints serialization compatibility #4092 (comment)
• FIx:minor fixes to receipt rpc endpoints serialization compatibility #4092 (comment)

[RazorClient]

This PR cleans up the RPC error handling semantics by introducing Result[Opt[T], string]-style handling into the RPC layer, allowing us to properly differentiate between:

• err(...) → invalid params / actual RPC errors
• ok(none(T)) → valid “not found” case returning null
• ok(some(T)) → successful response

The debug level failures are now removed from this pr as it doesn't fit in with the new ethjson
To be introduced with the follow-up ethjson pr