Changes to Add line

the data response's property type changed from no type to object for status 200

removed the request property customDiscount

removed the request property lineOrderInterval

removed the request property nextOrderId

removed the request property pricingType

added the new optional request property upsellProfileId

added the non-success response with the status 400

added the optional property data/id to the response with the 200 status

added the optional property data/name to the response with the 200 status

added the optional property data/price to the response with the 200 status

added the optional property data/quantity to the response with the 200 status

added the optional property data/shopifyId to the response with the 200 status

added the optional property pageInfo to the response with the 200 status