Updates an inventory item within the Nuport system. The inventory is uniquely mapped by the product and location in which the product resides. Ensure the location and product entities already exist in the system by calling their relevant APIs. This API acts as an "upsert" operation in that it will create new inventory if it does not exist in Nuport's system or it will update the inventory by the provided quantity provided. Note that an array of inventory data will be passed to this API and an array of created/updated inventory data will be returned in the order that they are passed in.