Align RPC error message to Ethereum's

[victhorbi]

Summary

We shall align the errors to Ethereum's.

Expected result is:

• find out the proper error code for this exception
• change the reference body below

{
    "jsonrpc": "2.0",
    "error": {
        "code": -32004,
        "message": "Method not supported"
    },
    "id": 9
}

And here's what we return:

{
    "jsonrpc": "2.0",
    "result": "METHOD NOT IMPLEMENTED",
    "id": 9
}

[claytonneal]

think we should use these error codes:

https://ethereum-json-rpc.com/errors

which is linked to from the ethereum docs
"code": -32042, is probably a custom error code from QuickNode/Infura ?

[claytonneal]

actually id be careful with the format - seems some RPC providers dont respect the RPC spec
we should probably look what Viem will de-serialise