feat: implement closing related features.

src/Ursa/Controls/Dialog/DialogBox.cs

@@ -58,7 +58,7 @@ public static class DialogBox
         };
         t.DataContext = vm;
         var host = OverlayDialogManager.GetOverlayDialogHost(hostId);
-        host?.Children.Add(t);
+        host?.AddDialog(t);
         return null;
     }
 }

src/Ursa/Controls/Dialog/DialogControl.cs

@@ -13,15 +13,36 @@ public class DialogControl: ContentControl
     
     
     private Button? _closeButton;
-    public event EventHandler OnClose;
+    public event EventHandler<object?> OnClose;
 
     protected override void OnApplyTemplate(TemplateAppliedEventArgs e)
     {
         base.OnApplyTemplate(e);
+        if (_closeButton != null)
+        {
+            _closeButton.Click -= Close;
+        }
+        _closeButton = e.NameScope.Find<Button>(PART_CloseButton);
+        if (_closeButton is not null)
+        {
+            _closeButton.Click += Close;
+        }
     }
 
     public void Show()
     {
         
     }
+
+    private void Close(object sender, object args)
+    {
+        if (this.DataContext is IDialogContext context)
+        {
+            OnClose?.Invoke(this, context.DefaultCloseResult);
+        }
+        else
+        {
+            OnClose?.Invoke(this, null);
+        }
+    }
 }

src/Ursa/Controls/Dialog/DialogOptions.cs

@@ -1,6 +1,6 @@
 namespace Ursa.Controls;
 
-public record OverlayDialogOptions
+public record DialogOptions
 {
     public bool ShowCloseButton { get; set; } = true;
 }

src/Ursa/Controls/Dialog/OverlayDialogHost.cs

@@ -84,6 +84,17 @@ public class OverlayDialogHost: Canvas
     public void AddDialog(DialogControl control)
     {
         this.Children.Add(control);
+        control.OnClose += OnDialogClose;
+    }
+
+    private void OnDialogClose(object sender, object? e)
+    {
+        if (sender is DialogControl control)
+        {
+            this.Children.Remove(control);
+            control.OnClose -= OnDialogClose;
+        }
+        
     }
 
     public void AddModalDialog(DialogControl control)