fix: Changes Map.Sector.Items to link list. (#1547)

### Summary

Eliminates `IPooledEnumerable<T>` and `eable.Free()` from `Map` for items. This drastically simplifies code that iterates in range, for example:

```cs
foreach (var item in m.GetItemsInRange(5))
{
}
```
The code above no longer requires an eable and calling `Free()`.

Projects/UOContent/Mobiles/AI/BaseAI.cs

@@ -2157,10 +2157,7 @@ public abstract class BaseAI
                 Movement.Movement.Offset(d, ref x, ref y);
 
                 var destroyables = 0;
-
-                var eable = map.GetItemsInRange(new Point3D(x, y, m_Mobile.Location.Z), 1);
-
-                foreach (var item in eable)
+                foreach (var item in map.GetItemsInRange(new Point3D(x, y, m_Mobile.Location.Z), 1))
                 {
                     if (canOpenDoors && item is BaseDoor door && door.Z + door.ItemData.Height > m_Mobile.Z &&
                         m_Mobile.Z + 16 > door.Z)

Projects/UOContent/Mobiles/BaseCreature.cs

@@ -3638,9 +3638,8 @@ namespace Server.Mobiles
                 return false;
             }
 
-            var eable = GetItemsInRange<Corpse>(2);
             Corpse toRummage = null;
-            foreach (var c in eable)
+            foreach (var c in GetItemsInRange<Corpse>(2))
             {
                 if (c.Items.Count > 0)
                 {

Projects/UOContent/Mobiles/Familiars/HordeMinion.cs

@@ -74,9 +74,8 @@ public partial class HordeMinionFamiliar : BaseFamiliar
             return;
         }
 
-        var eable = GetItemsInRange(2);
         using var queue = PooledRefQueue<Item>.Create();
-        foreach (var item in eable)
+        foreach (var item in GetItemsInRange(2))
         {
             if (item.Movable && item.Stackable)
             {

Projects/UOContent/Mobiles/Monsters/ML/Humanoid/Magic/InterredGrizzle .cs

@@ -117,9 +117,13 @@ namespace Server.Mobiles
                 {
                     p = GetSpawnPosition(2);
 
-                    var eable = Map.GetItemsInRange<StainedOoze>(p, 0);
-                    using var enumerator = eable.GetEnumerator();
-                    bool atLocation = enumerator.MoveNext();
+                    var atLocation = false;
+                    foreach (var item in Map.GetItemsInRange<StainedOoze>(p, 0))
+                    {
+                        atLocation = true;
+                        break;
+                    }
+
                     if (!atLocation)
                     {
                         break;

Projects/UOContent/Mobiles/Monsters/ML/Special/Ilhenir.cs

@@ -234,9 +234,13 @@ namespace Server.Mobiles
                 {
                     p = GetSpawnPosition(2);
 
-                    var eable = Map.GetItemsInRange<StainedOoze>(p, 0);
-                    using var enumerator = eable.GetEnumerator();
-                    bool atLocation = enumerator.MoveNext();
+                    var atLocation = false;
+                    foreach (var item in Map.GetItemsInRange<StainedOoze>(p, 0))
+                    {
+                        atLocation = true;
+                        break;
+                    }
+
                     if (!atLocation)
                     {
                         break;

Projects/UOContent/Mobiles/Monsters/Misc/Melee/PlagueBeast.cs

@@ -165,18 +165,13 @@ namespace Server.Mobiles
             base.OnThink();
 
             // Check to see if we need to devour any corpses
-            var eable = GetItemsInRange<Corpse>(3); // Get all corpses in range
-
-            foreach (var item in eable)
-                // Ensure that the corpse was killed by us
+            foreach (var item in GetItemsInRange<Corpse>(3)) // Get all corpses in range
             {
+                // Ensure that the corpse was killed by us
                 if (item.Killer == this && item.Owner != null && !item.DevourCorpse() && !item.Devoured)
                 {
-                    PublicOverheadMessage(
-                        MessageType.Emote,
-                        0x3B2,
-                        1053032
-                    ); // * The plague beast attempts to absorb the remains, but cannot! *
+                    // * The plague beast attempts to absorb the remains, but cannot! *
+                    PublicOverheadMessage(MessageType.Emote, 0x3B2, 1053032);
                 }
             }
         }