don't end sessions until acks can be sent

Author: jdomnitz

MatterDotNet/Protocol/Sessions/SessionContext.cs

@@ -62,11 +62,11 @@ internal async Task DeleteExchange(Exchange exchange)
 
         public void Dispose()
         {
-            SessionManager.RemoveSession(LocalSessionID);
             Console.WriteLine("Closing Session " + LocalSessionID);
             var keys = exchanges.Keys;
             foreach (var key in keys)
                 exchanges[key].Dispose();
+            SessionManager.RemoveSession(LocalSessionID);
             GC.SuppressFinalize(this);
         }
     }

MatterDotNet/Protocol/Sessions/SessionManager.cs

@@ -55,7 +55,7 @@ public static SessionContext GetUnsecureSession(IConnection connection, bool ini
 
         public static SessionContext? GetSession(ushort sessionId)
         {
-            if (sessions.TryGetValue(sessionId, out SessionContext ctx))
+            if (sessions.TryGetValue(sessionId, out SessionContext? ctx))
                 return ctx;
             return null;
         }