fix(core): Removes some uses of Linq (#421)

- [X] Removes some uses of linq
- [X] Creates struct based enumerator for Skills
- [X] Creates a struct based enumerator for TypeCache
- [X] Changes HarvestDefinition to an init array instead of List
- [X] Changes HeritageTokenGump Response from List to Array

Projects/UOContent/Engines/Help/HelpGump.cs

@@ -1,5 +1,4 @@
 using System;
-using System.Linq;
 using Server.Engines.ConPVP;
 using Server.Factions;
 using Server.Gumps;
@@ -294,9 +293,12 @@ namespace Server.Engines.Help
 
         private static void EventSink_HelpRequest(Mobile m)
         {
-            if (m.NetState.Gumps.OfType<HelpGump>().Any())
+            foreach (var gump in m.NetState.Gumps)
             {
-                return;
+                if (gump is HelpGump)
+                {
+                    return;
+                }
             }
 
             if (!PageQueue.CheckAllowedToPage(m))