question/bug: Is there a way to use custom errors for Goa's internal errors?

The example here shows how to return a custom error: https://github.com/goadesign/examples/blob/master/error/calc.go#L26
This is good but if one wants to customize the error type for a whole service, Goa still uses its own underlying `ErrorResult` type
which can not be customized at the moment or am I missing something?

Also the `client` uses `ClientError`: from `goa/v3/http/client.go`:

and a decode function in the `client/encode_decode.go` is generated like the blow extract
and any `server` error due to request decoding (`ErrorResult`) (e.g. missing field)
**gets mapped into the `default: ` case** which returns a `gohttp.ErrInvalidResponse`. **Is this correct?**
We defined the errors `cm#bad-request` and `cm#invalid-contract` etc.

**Encode/Decode in Client:*
```go
func DecodeCreateContractResponse(decoder func(*http.Response) goahttp.Decoder, restoreBody bool) func(*http.Response) (any, error) {
return func(resp *http.Response) (any, error) {
// redacted .........
switch resp.StatusCode {
case http.StatusOK:
// redacted ...
case http.StatusBadRequest:
en := resp.Header.Get("goa-error")
switch en {
case "cm#bad-request":
var (
body CreateContractCmBadRequestResponseBody
err error
)
err = decoder(resp).Decode(&body)
if err != nil {
return nil, goahttp.ErrDecodingError("cm", "createContract", err)
}
err = ValidateCreateContractCmBadRequestResponseBody(&body)
if err != nil {
return nil, goahttp.ErrValidationError("cm", "createContract", err)
}
return nil, NewCreateContractCmBadRequest(&body)
case "cm#contract-invalid":
var (
body CreateContractCmContractInvalidResponseBody
err error
)
err = decoder(resp).Decode(&body)
if err != nil {
return nil, goahttp.ErrDecodingError("cm", "createContract", err)
}
err = ValidateCreateContractCmContractInvalidResponseBody(&body)
if err != nil {
return nil, goahttp.ErrValidationError("cm", "createContract", err)
}
return nil, NewCreateContractCmContractInvalid(&body)
default:
body, _ := io.ReadAll(resp.Body)
return nil, goahttp.ErrInvalidResponse("cm", "createContract", resp.StatusCode, string(body))
}
```