feat: initialize dialog.

src/Ursa/Controls/Dialog/DialogBox.cs

@@ -0,0 +1,20 @@
+using Avalonia.Controls;
+
+namespace Ursa.Controls;
+
+public static class DialogBox
+{
+    public static async Task ShowAsync()
+    {
+        return;
+    }
+
+    public static async Task ShowAsync<TView, TViewModel>(TViewModel vm) 
+        where TView: Control, new()
+        where TViewModel: new()
+    {
+        TView t = new TView();
+        t.DataContext = vm;
+        return;
+    }
+}