Added DoHandleReset method for websocket subscriptions

CryptoExchange.Net/Sockets/SocketConnection.cs

@@ -268,7 +268,7 @@ namespace CryptoExchange.Net.Sockets
             lock (_listenersLock)
             {
                 foreach (var subscription in _listeners.OfType<Subscription>().Where(l => l.UserSubscription))
-                    subscription.Confirmed = false;
+                    subscription.Reset();
 
                 foreach (var query in _listeners.OfType<Query>().ToList())
                 {
@@ -293,7 +293,7 @@ namespace CryptoExchange.Net.Sockets
             lock (_listenersLock)
             {
                 foreach (var subscription in _listeners.OfType<Subscription>().Where(l => l.UserSubscription))
-                    subscription.Confirmed = false;
+                    subscription.Reset();
 
                 foreach (var query in _listeners.OfType<Query>().ToList())
                 {

CryptoExchange.Net/Sockets/Subscription.cs

@@ -130,6 +130,20 @@ namespace CryptoExchange.Net.Sockets
             return Task.FromResult(DoHandleMessage(connection, message));
         }
 
+        /// <summary>
+        /// Reset the subscription
+        /// </summary>
+        public void Reset()
+        {
+            Confirmed = false;
+            DoHandleReset();
+        }
+
+        /// <summary>
+        /// Connection has been reset, do any logic for resetting the subscription
+        /// </summary>
+        public virtual void DoHandleReset() { }
+
         /// <summary>
         /// Handle the update message
         /// </summary>