Websocket connection performance improvements, Added multiple options, SymbolOrderBook improvements

CryptoExchange.Net/Sockets/UpdateSubscription.cs

@@ -1,4 +1,5 @@
-using System;
+using CryptoExchange.Net.Objects;
+using System;
 using System.Threading.Tasks;
 
 namespace CryptoExchange.Net.Sockets
@@ -91,5 +92,23 @@ namespace CryptoExchange.Net.Sockets
         {
             return connection.Socket.CloseAsync();
         }
+
+        /// <summary>
+        /// Unsubscribe a subscription
+        /// </summary>
+        /// <returns></returns>
+        internal async Task UnsubscribeAsync()
+        {
+            await connection.UnsubscribeAsync(subscription).ConfigureAwait(false);
+        }
+
+        /// <summary>
+        /// Resubscribe this subscription
+        /// </summary>
+        /// <returns></returns>
+        internal async Task<CallResult<bool>> ResubscribeAsync()
+        {
+            return await connection.ResubscribeAsync(subscription).ConfigureAwait(false);
+        }
     }
 }