fix(core): Adds Gump component functionality (#377)

- [X] Adds gump close packet
- [X] Fixes gump tooltip
- [X] Adds new compile/append functions for the new gump packets

Projects/Server/Network/Packets/OutgoingGumpPackets.cs

@@ -0,0 +1,40 @@
+/*************************************************************************
+ * ModernUO                                                              *
+ * Copyright (C) 2019-2020 - ModernUO Development Team                   *
+ * Email: hi@modernuo.com                                                *
+ * File: OutgoingGumpPackets.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.Buffers;
+
+namespace Server.Network
+{
+    public static class OutgoingGumpPackets
+    {
+        public static void SendCloseGump(this NetState ns, int typeId, int buttonId)
+        {
+            if (ns == null || !ns.GetSendBuffer(out var buffer))
+            {
+                return;
+            }
+
+            var writer = new CircularBufferWriter(buffer);
+            writer.Write((byte)0xBF); // Packet ID
+            writer.Write((ushort)13);
+
+            writer.Write((short)0x04);
+            writer.Write(typeId);
+            writer.Write(buttonId);
+
+            ns.Send(ref buffer, writer.Position);
+        }
+    }
+}