feat: better document rejection (#1702)

Improves the existing document rejection process by actually marking a
document as completed cancelling further actions.

## Related Issue

N/A

## Changes Made

- Added a new rejection status for documents
- Updated a million areas that check for document completion
- Updated email sending, so rejection is confirmed for the rejecting
recipient while other recipients are notified that the document is now
cancelled.

## Testing Performed

- Ran the testing suite to ensure there are no regressions.
- Performed manual testing of current core flows.

packages/lib/server-only/admin/get-documents-stats.ts

@@ -13,6 +13,7 @@ export const getDocumentStats = async () => {
     [ExtendedDocumentStatus.DRAFT]: 0,
     [ExtendedDocumentStatus.PENDING]: 0,
     [ExtendedDocumentStatus.COMPLETED]: 0,
+    [ExtendedDocumentStatus.REJECTED]: 0,
     [ExtendedDocumentStatus.ALL]: 0,
   };