Limit timetable scrolling so no errors occur

lib/model/timetable/timetableProps.dart

@@ -105,4 +105,17 @@ class TimetableProps extends DataHolder {
       notifyListeners();
     }
   }
+
+  void resetWeek()  {
+    error = null;
+    notifyListeners();
+
+    DateTime queryWeek = DateTime.now().add(const Duration(days: 2));
+
+    startDate = getDate(queryWeek.subtract(Duration(days: queryWeek.weekday - 1)));
+    endDate = getDate(queryWeek.add(Duration(days: DateTime.daysPerWeek - queryWeek.weekday)));
+
+    run();
+    notifyListeners();
+  }
 }