Single link
`POST /v1/links` with exactly one of `url` or `longUrl`. Active responses include dual short URLs and the QR tracking URL.
- Always:
state,status_url,request_id - Active only:
short_url,short_url_ascii,destination,qr_tracking_url
`POST /v1/links` with exactly one of `url` or `longUrl`. Active responses include dual short URLs and the QR tracking URL.
state, status_url, request_idshort_url, short_url_ascii, destination, qr_tracking_url