* Backend setup for proposal canceling.
* Cancelable in admin, update all states to properly reflect a canceled proposal.
* Replace REFUNDING stage with CANCELED and FAILED to distinguish between the 2
* Fix pending contributions showing up as needing refunds.
* Fix some refund cases.
* Dont show failed & canceled proposals on list view. Hide their filters.
* Show when proposal was canceled.
* Remove edit action, make cancel an explanation to contact support.
* Fix PR comments
* Fix issues from develop merge.
William O'Beirne