DeliveryRateProvider union
Rate provided by a rate definition or a participant.
Possible types
[DeliveryParticipant](https://shopify.dev/docs/admin-api/graphql/reference/shipping-and-fulfillment/deliveryparticipant)
[DeliveryRateDefinition](https://shopify.dev/docs/admin-api/graphql/reference/shipping-and-fulfillment/deliveryratedefinition)