Remove instance logic for BinaryStorage and JsonStorage, part 1

1. part of #389
2. huge refactoring

Plugins/Wox.Plugin.Folder/FolderStorage.cs

@@ -4,11 +4,10 @@ using Wox.Infrastructure.Storage;
 
 namespace Wox.Plugin.Folder
 {
-    public class FolderStorage : JsonStrorage<FolderStorage>
+    public class Settings
     {
         [JsonProperty]
         public List<FolderLink> FolderLinks { get; set; }
 
-        protected override string FileName { get; } = "settings_folder_plugin";
     }
 }