Use create_payment everywhere

Job Doesburg
2020-03-09T17:59:50+01:00

Use create_payment (from #1010 ) everywhere where we use payments

### Why?

Prevent code duplication

### Current implementation

Shitty, chaotic, anarchy, tears

### Suggested implementation

Make models Payable (implement the interface / abstract class from #1010) and use `create_payment` as the only way to interact with / create payments.