add Uri parser, add ISerializationBinder

ISerializationBinder is added only in whitelist mode. Types for whitelisting should be registered manually via new API `Module.StartAsync()` or attribute `AllowedSerializableType(name)`

Core/UriBotParser.cs

@@ -0,0 +1,15 @@
+using BotFramework;
+using System;
+
+namespace Kruzya.TelegramBot.Core
+{
+    public class AbsoluteUriParser : IParameterParser<Uri>
+    {
+        public Uri DefaultInstance() => null;
+
+        public bool TryGetValue(string text, out Uri result)
+        {
+            return Uri.TryCreate(text, UriKind.Absolute, out result);
+        }
+    }
+}