Delete budget project folder if the budget creation process is terminated halfway

src/main/java/no/ntnu/idatt1002/demo/controller/BudgetController.java

@@ -315,6 +315,8 @@ public class BudgetController extends FinanceController {
                 loader.setLocation(getClass().getResource("/view/dualList.fxml"));
             } else if (event.getSource() == returnBtn) {
                 loader.setLocation(getClass().getResource("/view/FirstMenu.fxml"));
+                FileHandlingBudgetArchive.deleteBudgetDirectory(FileHandlingSelectedBudget.readSelectedBudget());
+                FileHandlingSelectedBudget.clearSelectedBudget();
             }
             saveDataToFile();
             Parent root = loader.load();