* Feature #307 : New windows setting to use cover art as folder's icon. Incomplete. Need to add to avalonia settings

* Interop refactor

Source/LibationFileManager/NullInteropFunctions.cs

@@ -0,0 +1,13 @@
+using System;
+
+namespace LibationFileManager
+{
+    public class NullInteropFunctions : IInteropFunctions
+    {
+        public NullInteropFunctions() { }
+        public NullInteropFunctions(params object[] values) { }
+
+        public void SetFolderIcon(string image, string directory) => throw new PlatformNotSupportedException();
+        public void DeleteFolderIcon(string directory) => throw new PlatformNotSupportedException();
+    }
+}