The Create Transaction Event function allows the Device to report the product
the user purchased to the Tiliter Recognition API.
This is used to close the loop on the transaction and record when the Device
was used to follow through and purchase a product.
This also eliminates irrelevant data from reports that may result from
incomplete transactions.
Every recognition requires a transaction report; if no transaction occurs,
that can also be reported.

Transaction events are reported per recognition, using the recognition_id
returned by the recognition request. There is no single report for the
whole transaction.
Each event must be reported within 30 minutes of its recognition. After that
the recognition can no longer be found and the request returns 404.
Events can be reported as they happen, or together once the transaction is
completed and paid using the Create Transaction Events In Batch function,
as long as each event is within 30 minutes of its recognition.

When loss is reported, use the following event types:
loss_actioned: store staff checked and it was loss, and the product was
removed from the cart.
purchased: store staff checked and it was not loss, and the product was
purchased. This tells us the loss report was incorrect and is used to
improve recognition.
loss_acknowledged: the shopper was asked to confirm (e.g. "are you sure?")
and proceeded anyway.