Changes to Subscribe to a status page

added the new SERVICE_UNAVAILABLE enum value to the code response property for the response status 400

added the new SERVICE_UNAVAILABLE enum value to the code response property for the response status 401

added the new SERVICE_UNAVAILABLE enum value to the code response property for the response status 402

added the new SERVICE_UNAVAILABLE enum value to the code response property for the response status 403

added the new SERVICE_UNAVAILABLE enum value to the code response property for the response status 404

added the new SERVICE_UNAVAILABLE enum value to the code response property for the response status 409

added the new SERVICE_UNAVAILABLE enum value to the code response property for the response status 500

added the new TOO_MANY_REQUESTS enum value to the code response property for the response status 400

added the new TOO_MANY_REQUESTS enum value to the code response property for the response status 401

added the new TOO_MANY_REQUESTS enum value to the code response property for the response status 402

added the new TOO_MANY_REQUESTS enum value to the code response property for the response status 403

added the new TOO_MANY_REQUESTS enum value to the code response property for the response status 404

added the new TOO_MANY_REQUESTS enum value to the code response property for the response status 409

added the new TOO_MANY_REQUESTS enum value to the code response property for the response status 500

added the non-success response with the status 429

added the non-success response with the status 503