fix: Handle Reset action in OnCollectionChanged method

Introduce code to handle NotifyCollectionChangedAction.Reset in the
OnCollectionChanged method. When a reset occurs, the code checks if
the sender is an IEnumerable, iterates through the items, and updates
the OnItemPropertyChangedCallbackAsync event handler for each item
implementing INotifyPropertyChanged. Finally, it calls the
RefreshAppointments method to ensure all items are properly updated.

src/MyNet.Wpf/Controls/CalendarBase.cs

@@ -366,7 +366,16 @@ private async void OnAppointmentsCollectionChangedCallbackAsync(object? sender,
             if (_refreshAppointmentsSuspender.IsSuspended) return;
 
             if (e.Action == NotifyCollectionChangedAction.Reset)
+            {
+                if (sender is IEnumerable enumerable)
+                    foreach (var item in enumerable.OfType<INotifyPropertyChanged>())
+                    {
+                        item.PropertyChanged -= OnItemPropertyChangedCallbackAsync;
+                        item.PropertyChanged += OnItemPropertyChangedCallbackAsync;
+                    }
+
                 RefreshAppointments();
+            }
             else
             {
                 await Dispatcher.Invoke(() => BusyService).WaitAsync<IndeterminateBusy>(async _ =>