fix(network): Adds ConnectUO (#551)

- [X] Adds ability to create new protocol extension packets
- [X] Adds freeshard protocol extension support (packet 0xF1)
- [X] Adds ConnectUO support
- [X] Adds arbitrary read for `CircularBufferReader` and `SpanReader`

Projects/UOContent/Network/FreeshardProtocol.cs

@@ -0,0 +1,31 @@
+/*************************************************************************
+ * ModernUO                                                              *
+ * Copyright (C) 2019-2021 - ModernUO Development Team                   *
+ * Email: hi@modernuo.com                                                *
+ * File: FreeshardProtocol.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/>. *
+ *************************************************************************/
+
+namespace Server.Network
+{
+    public static class FreeshardProtocol
+    {
+        private static PacketHandler[] _handlers;
+
+        [CallPriority(10)]
+        public static void Configure()
+        {
+            _handlers = ProtocolExtensions.Register(0xF1);
+        }
+
+        public static void Register(int cmd, bool ingame, OnPacketReceive onReceive) =>
+            _handlers[cmd] = new PacketHandler(cmd, 0, ingame, onReceive);
+    }
+}