Track StockX listing operations and reconcile completed orders via the Selling API

Steps

1. Authenticate with the same Bearer token + x-api-key pair used for listing creation
2. GET the listing-operations endpoint to check the async status of a submitted create/update/delete listing call
3. GET the active listings and orders resources under /v2/selling to reconcile which asks converted to completed sales
4. Update or delete an existing listing by submitting a new async operation against its listing ID
5. Inspect an operation's status/error payload before retrying a failed create or update