Added source_location field to FulfillmentOrdersMove webhook payload

As of API version 2023-04, FulfillmentOrdersMove webhook payload is extended source_location field.

The assignedLocation of the original_fulfillment_order may be changed by the move operation. Therefore, if you need to determine the originally assigned location, you should refer to the source_location field.

Learn more about fulfillment order move in the FulfillmentOrdersMove webhook, FulfillmentOrdersMove GraphQL mutation and Moves a fulfillment order to a new location REST endpoint documentation pages.