Implement TryGetFeature on secondary previewer windows (#17409)

src/Avalonia.DesignerSupport/Remote/Stubs.cs

@@ -197,7 +197,20 @@ namespace Avalonia.DesignerSupport.Remote
         public void SetFrameThemeVariant(PlatformThemeVariant themeVariant) { }
 
         public AcrylicPlatformCompensationLevels AcrylicCompensationLevels { get; } = new AcrylicPlatformCompensationLevels(1, 1, 1);
-        public object TryGetFeature(Type featureType) => null;
+        public object TryGetFeature(Type featureType)
+        {
+            if (featureType == typeof(IStorageProvider))
+            {
+                return new NoopStorageProvider();
+            }
+
+            if (featureType == typeof(IScreenImpl))
+            {
+                return new ScreenStub();
+            }
+
+            return null;
+        }
         public void TakeFocus() { }
     }