Create a "cancel registration" button which is distinct from "Refund"

[dunkOnIT]

Text below quoted from #5162:

...maybe have a cancel registration button that's separate from a refund button? The cancel registration button would automatically delete the competitor's registration and would refund the correct percentage. This could be confusing though as refund and cancelling might not be as distinct as I think it is (or the distinction may be less obvious to some people).