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/Spells/Seventh/GateTravel.cs

@@ -1,5 +1,4 @@
 using System;
-using System.Linq;
 using Server.Factions;
 using Server.Items;
 using Server.Misc;
@@ -127,10 +126,16 @@ namespace Server.Spells.Seventh
         private bool GateExistsAt(Map map, Point3D loc)
         {
             var eable = map.GetItemsInRange(loc, 0);
-            var gateFound = eable.Any(item => item is Moongate || item is PublicMoongate);
-            eable.Free();
 
-            return gateFound;
+            foreach (var item in eable)
+            {
+                if (item is Moongate || item is PublicMoongate)
+                {
+                    return true;
+                }
+            }
+
+            return false;
         }
 
         [DispellableField]

Projects/UOContent/Spells/Seventh/MeteorSwarm.cs

@@ -79,9 +79,7 @@ namespace Server.Spells.Seventh
                     targets = new List<Mobile>();
                 }
 
-                double damage;
-
-                damage = Core.AOS
+                double damage = Core.AOS
                     ? GetNewAosDamage(51, 1, 5, playerVsPlayer)
                     : Utility.Random(27, 22);