fix(core): Tightens the network stack (#479)

- [X] Removes network pause/resume
- [X] Adds back packet profiler
- [X] Adds state machine to keep track and trace netstates
- [X] Changes NetState.Running back to using an interlock exchange
- [X] Adds preliminary packet throttling support


### Packet Throttling
- `[GetThrottle <packetId>` to get the delay in milliseconds for that packet
- `[SetThrottle <packetId> <delay>` to set the delay in milliseconds for that packet
The settings are saved to `Configuration/throttles.json`

Projects/Server/Network/NetState/DumpNetStates.cs

@@ -0,0 +1,39 @@
+/*************************************************************************
+ * ModernUO                                                              *
+ * Copyright (C) 2019-2021 - ModernUO Development Team                   *
+ * Email: hi@modernuo.com                                                *
+ * File: DumpNetStates.cs                                                *
+ *                                                                       *
+ * This program is free software: you can redistribute it and/or modify  *
+ * it under the terms of the GNU General Public License as published by  *
+ * the Free Software Foundation, either version 3 of the License, or     *
+ * (at your option) any later version.                                   *
+ *                                                                       *
+ * You should have received a copy of the GNU General Public License     *
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>. *
+ *************************************************************************/
+
+using System.IO;
+
+namespace Server.Network
+{
+    public static class DumpNetStates
+    {
+        public static void Initialize()
+        {
+            CommandSystem.Register("DumpNetStates", AccessLevel.Administrator, DumpNetStatesCommand);
+        }
+
+        public static void DumpNetStatesCommand(CommandEventArgs args)
+        {
+            using var file = new StreamWriter("netstatedump.csv");
+
+            file.WriteLine("NetState, RecvTask, SendTask, ProtocolState, ParserState");
+
+            foreach (var ns in TcpServer.Instances)
+            {
+                file.WriteLine($"{ns}, {ns._recvState}, {ns._sendState}, {ns._protocolState}, {ns._parserState}");
+            }
+        }
+    }
+}