Add backup and restore

v2rayN/ServiceLib/Models/Config.cs

@@ -47,6 +47,7 @@
         public HysteriaItem hysteriaItem { get; set; }
         public ClashUIItem clashUIItem { get; set; }
         public SystemProxyItem systemProxyItem { get; set; }
+        public WebDavItem webDavItem { get; set; }
         public List<InItem> inbound { get; set; }
         public List<KeyEventItem> globalHotkeys { get; set; }
         public List<CoreTypeItem> coreTypeItem { get; set; }

v2rayN/ServiceLib/Models/ConfigItems.cs

@@ -248,4 +248,12 @@
         public bool notProxyLocalAddress { get; set; } = true;
         public string systemProxyAdvancedProtocol { get; set; }
     }
+
+    [Serializable]
+    public class WebDavItem
+    {
+        public string? url { get; set; }
+        public string? userName { get; set; }
+        public string? password { get; set; }
+    }
 }