R1:d6eb1c67e769

Phortune Cart Status, some one-time support

Summary:
Ref T2787. Carts need a status so we can tell if they've been purchased. Also kind of get WePay working as a one-time provider, and let charges not have a methodPHID (they won't for one-time providers).

All the status stuff is still super crazy rough and you can do things like start a checkout, add a bunch of stuff to your cart, complete the checkout, and have Phabricator think you paid for all the stuff you added. But this is fine for now since you…