Fix Browser not wrapping file handles into StorageItem object

src/Browser/Avalonia.Browser/Interop/StorageHelper.cs

@@ -39,6 +39,9 @@ internal static partial class StorageHelper
 
     [JSImport("StorageItem.openRead", AvaloniaModule.StorageModuleName)]
     public static partial Task<JSObject> OpenRead(JSObject item);
+    
+    [JSImport("StorageItem.createFromHandle", AvaloniaModule.StorageModuleName)]
+    public static partial JSObject? StorageItemFromHandle(JSObject handle);
 
     [JSImport("StorageItem.getItemsIterator", AvaloniaModule.StorageModuleName)]
     [return: JSMarshalAs<JSType.Object>]

src/Browser/Avalonia.Browser/Storage/BrowserStorageProvider.cs

@@ -319,13 +319,14 @@ internal class JSStorageFolder : JSStorageItem, IStorageBookmarkFolder
             }
 
             var kind = storageItem.GetPropertyAsString("kind");
+            var item = StorageHelper.StorageItemFromHandle(storageItem)!;
             switch (kind)
             {
                 case "directory":
-                    yield return new JSStorageFolder(storageItem);
+                    yield return new JSStorageFolder(item);
                     break;
                 case "file":
-                    yield return new JSStorageFile(storageItem);
+                    yield return new JSStorageFile(item);
                     break;
             }
         }