Updates to error codes for translationsRegister

Although the INVALID_LOCALE_FOR_SHOP error code was introduced in the 2020-07 version, it has never been used to represent a locale field related error when calling the translationsRegister mutation.

As of GraphQL Admin API version 2022-04, the INVALID_LOCALE_FOR_SHOP error code is used to represent all errors related to the locale field on the Translation object.

Previous verions will still use the INVALID_CODE error code to represent errors related to the locale field.