[GO] Returns the correct data type from New**FromValue func for enums

[simodima]

Fixes #20084
Returns the correct data type

Returning the correct data type from the GO server function New{{{classname}}}FromValue
The current implementation has a bug since it always returns an empty string when the ev is not valid.

Previous bugged code

func NewErrorCodesFromValue(v int32) (ErrorCodes, error) {
	ev := ErrorCodes(v)
	if ev.IsValid() {
		return ev, nil
	}

	return "", fmt.Errorf("invalid value '%v' for ErrorCodes: valid values are %v", v, AllowedErrorCodesEnumValues)
}

The fixed code

func NewErrorCodesFromValue(v int32) (ErrorCodes, error) {
	ev := ErrorCodes(v)
	if ev.IsValid() {
		return ev, nil
	}
	noValue := new(ErrorCodes)
	return *noValue, fmt.Errorf("invalid value '%v' for ErrorCodes: valid values are %v", v, AllowedErrorCodesEnumValues)
}

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[simodima]

Mentioning @antihax @grokify @kemokemo @jirikuncar @ph4r5h4d @lwj5 as per the

@mention the technical committee members