feat: WIP dialog window.

src/Ursa/Controls/Dialog/DialogControl.cs

@@ -1,8 +1,27 @@
 using Avalonia.Controls;
+using Avalonia.Controls.Metadata;
+using Avalonia.Controls.Primitives;
+using Avalonia.Interactivity;
 
 namespace Ursa.Controls;
 
+[TemplatePart(PART_CloseButton, typeof(Button))]
 public class DialogControl: ContentControl
 {
+    public const string PART_CloseButton = "PART_CloseButton";
     
+    
+    
+    private Button? _closeButton;
+    public event EventHandler OnClose;
+
+    protected override void OnApplyTemplate(TemplateAppliedEventArgs e)
+    {
+        base.OnApplyTemplate(e);
+    }
+
+    public void Show()
+    {
+        
+    }
 }