Adding point works

Views/EditPointDialog.axaml.cs

@@ -0,0 +1,18 @@
+using Avalonia.Controls;
+using CommunityToolkit.Mvvm.Messaging;
+using GazpromApp.Messages;
+
+namespace GazpromApp.Views;
+
+public partial class EditPointDialog : Window
+{
+    public EditPointDialog()
+    {
+        InitializeComponent();
+        
+        WeakReferenceMessenger.Default.Register<EditPointDialog, EditPointDone>(this, static (w, m) =>
+        {
+            w.Close(m.Point);
+        });
+    }
+}