Migrate image sector viewer from Eto.Forms to Avalonia.

Aaru.Gui/Views/ViewSectorWindow.xaml.cs

@@ -0,0 +1,19 @@
+using Avalonia;
+using Avalonia.Controls;
+using Avalonia.Markup.Xaml;
+
+namespace Aaru.Gui.Views
+{
+    public class ViewSectorWindow : Window
+    {
+        public ViewSectorWindow()
+        {
+            InitializeComponent();
+        #if DEBUG
+            this.AttachDevTools();
+        #endif
+        }
+
+        void InitializeComponent() => AvaloniaXamlLoader.Load(this);
+    }
+}