fix: Changes Map.Sector.Mobiles to link list & Fixes various related crash bugs (#1553)

### Summary

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

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

- [X] Fixed several locations where an NPC that was damaged would cause a server crash.
- [X] Removed an unnecessary allocation in guard fake calls (NPCs calling guards on you)
- [X] Fixes damage precision loss in Poison Strike Spell
- [X] BogThing no longer attempts to "search" for boglings to eat when it is at full health

Projects/UOContent/Spells/Necromancy/PoisonStrike.cs

@@ -80,8 +80,7 @@ namespace Server.Spells.Necromancy
                     var cbc = Caster as BaseCreature;
                     var isMonster = cbc?.Controlled == false && (cbc.IsAnimatedDead || !cbc.Summoned);
 
-                    var eable = m.GetMobilesInRange(2);
-                    foreach (Mobile targ in eable)
+                    foreach (Mobile targ in m.GetMobilesInRange(2))
                     {
                         if (targ == Caster || m == targ || !SpellHelper.ValidIndirectTarget(Caster, targ)
                             || !Caster.CanBeHarmful(targ, false))