Thalia Pay: also enable late-cancellation fines to happen with Thalia Pay
One-sentence description
Also enable late-cancellation fines to happen with Thalia Pay
Motivation
Because it is weird to do let this happen via invoices if people normally can pay with Thalia Pay
Desired functionality
Currently if somebody wants has said to pay with Thalia Pay, but cancels, we delete the payment. After the event, the treasurer should be able to determine the real amount of the fine and have some action available to add TPAY payments for everyone that was too late and deserves a fine (now we will probably need to reopen #821 (closed) heheheheh)
Suggested implementation
To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information