return upstream error code to the client

[praveenweb]

The codegen for error handling looks like this:

if (errors) {
    return res.status(400).json(errors[0])
}

This doesn't send the code received in the errors[0].extensions object and only sends the message. Ideally the codegen should send back the error code as it is to the client.

The updated error handling would look like this:

if (errors) {
    return res.status(400).json( { code: errors[0].extensions.code, message: errors[0].message } );
}