adding GetObject and SaveObject methods for custom session serialization

- adding GetObject and SaveObject methods for custom session serialization

TelegramBotBase/Args/LoadStateEventArgs.cs

@@ -54,5 +54,10 @@ namespace TelegramBotBase.Args
             return false;
         }
 
+        public object GetObject(String key)
+        {
+            return Values[key];
+        }
+
     }
 }

TelegramBotBase/Args/SaveStateEventArgs.cs

@@ -32,6 +32,10 @@ namespace TelegramBotBase.Args
         {
             Values[key] = value;
         }
+        public void SetObject(String key, object value)
+        {
+            Values[key] = value;
+        }
 
     }
 }