feat: add close button.

demo/Ursa.Demo/Pages/ToastDemo.axaml

@@ -12,6 +12,7 @@
         <vm:ToastDemoViewModel />
     </Design.DataContext>
     <StackPanel>
+        <ToggleSwitch IsChecked="{Binding ShowClose}" Content="ShowClose"/>
         <StackPanel Orientation="Horizontal" Spacing="20">
             <Button Command="{Binding ShowNormal}" CommandParameter="{Binding $self.Content}" Content="Information" />
             <Button Command="{Binding ShowNormal}" CommandParameter="{Binding $self.Content}" Content="Success" Classes="Success" />

demo/Ursa.Demo/ViewModels/ToastDemoViewModel.cs

@@ -10,6 +10,9 @@ public partial class ToastDemoViewModel : ObservableObject
 {
     public WindowToastManager? ToastManager { get; set; }
 
+    [ObservableProperty]
+    private bool _showClose = true;
+
     [RelayCommand]
     public void ShowNormal(object obj)
     {
@@ -18,6 +21,7 @@ public partial class ToastDemoViewModel : ObservableObject
             Enum.TryParse<NotificationType>(s, out var notificationType);
             ToastManager?.Show(
                 new Toast("This is message"),
+                showClose: ShowClose,
                 type: notificationType);
         }
 
@@ -36,6 +40,7 @@ public partial class ToastDemoViewModel : ObservableObject
             Enum.TryParse<NotificationType>(s, out var notificationType);
             ToastManager?.Show(
                 new Toast("This is message"),
+                showClose: ShowClose,
                 type: notificationType,
                 classes: ["Light"]);
         }