Added abandon exam/exercise handler

src/pages/exercises.tsx

@@ -334,7 +334,9 @@ export default function Page() {
 								abandonPopupDescription="Are you sure you want to leave the exercise? You will lose all your progress."
 								abandonConfirmButtonText="Confirm"
 								onAbandon={() => {
-									console.log('TODO: Handle Abandon');
+									setExam(undefined);
+									setSelectedModules([]);
+									setShowAbandonPopup(false)
 									return true;
 								}}
 								onCancel={() => setShowAbandonPopup(false)}