CalendarDatePicker's dropdown popup should close when the calendar gets hidden

[MrJul]

Describe the bug

When a CalendarDatePicker gets hidden, its date dropdown stays open.
It should be closed instead.

ComboBox does this correctly.

To Reproduce

XAML:

<CalendarDatePicker x:Name="Picker" CalendarOpened="OnPickerCalendarOpened" />

Code-behind:

private void OnPickerCalendarOpened(object? sender, EventArgs e)
    => DispatcherTimer.RunOnce(() => Picker.IsVisible = false, TimeSpan.FromSeconds(2));

Open the calendar and wait 2 seconds.

Expected behavior

The calendar's dropdown list should close.

Avalonia version

11.0.10, 11.1.0-beta2, master 5e323b8

OS

No response

Additional context

No response

[rabbitism]

Since ComboBox implementation utilized internal CompositeDisposable and closing popup upon parent invisible is a common scenario (at least when I was designing Ursa), I hope popup can expose an API for this.