Changes to Get collection offer aggregates

the response property next became nullable for the status 200

the response property offer_aggregates/items/offer_price/symbol became nullable for the status 200

the response property offer_aggregates/items/total_value/symbol became nullable for the status 200

added the media type */* for the response with the status 400

added the optional property code to the response with the 401 status

added the optional property code to the response with the 403 status

added the optional property code to the response with the 404 status

added the optional property code to the response with the 409 status