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/Gumps/GumpEntry.cs

@@ -1,3 +1,5 @@
+using System.Buffers;
+using Server.Collections;
 using Server.Network;
 
 namespace Server.Gumps
@@ -23,6 +25,11 @@ namespace Server.Gumps
         }
 
         public abstract string Compile(NetState ns);
+        public abstract string Compile(OrderedHashSet<string> strings);
         public abstract void AppendTo(NetState ns, IGumpWriter disp);
+
+        // TODO: Replace OrderedHashSet with InsertOnlyHashSet, a copy of HashSet that is ReadOnly compatible, but includes
+        // a public AddIfNotPresent function that returns the index of the element
+        public abstract void AppendTo(ref SpanWriter writer, OrderedHashSet<string> strings, ref int entries, ref int switches);
     }
 }