Core/Creature: Allow to skip Rate.Corpse.Decay.Looted when calling SetCorpseDelay()

Port From (https://github.com/TrinityCore/TrinityCore/commit/a4a3e2e75999230d0d2e38886eef4ce0271f4a1d)

Source/Game/AI/SmartScripts/SmartAIManager.cs

@@ -3143,6 +3143,7 @@ namespace Game.AI
         public struct CorpseDelay
         {
             public uint timer;
+            public uint includeDecayRatio;
         }
         public struct DisableEvade
         {

Source/Game/AI/SmartScripts/SmartScript.cs

@@ -2178,7 +2178,7 @@ namespace Game.AI
                 {
                     foreach (var target in targets)
                         if (IsCreature(target))
-                            target.ToCreature().SetCorpseDelay(e.Action.corpseDelay.timer);
+                            target.ToCreature().SetCorpseDelay(e.Action.corpseDelay.timer, e.Action.corpseDelay.includeDecayRatio == 0);
                     break;
                 }
                 case SmartActions.SpawnSpawngroup:

Source/Game/Entities/Creature/Creature.Fields.cs

@@ -81,6 +81,7 @@ namespace Game.Entities
         long m_respawnTime;                               // (secs) time of next respawn
         uint m_respawnDelay;                              // (secs) delay between corpse disappearance and respawning
         uint m_corpseDelay;                               // (secs) delay between death and corpse disappearance
+        bool m_ignoreCorpseDecayRatio;
         float m_wanderDistance;
         uint m_boundaryCheckTime;                         // (msecs) remaining time for next evade boundary check
         uint m_combatPulseTime;                           // (msecs) remaining time for next zone-in-combat pulse

Source/Game/Entities/Creature/Creature.cs

@@ -2593,7 +2593,9 @@ namespace Game.Entities
             if (m_corpseRemoveTime <= now)
                 return;
 
-            float decayRate = WorldConfig.GetFloatValue(WorldCfg.RateCorpseDecayLooted);
+            // Scripts can choose to ignore RATE_CORPSE_DECAY_LOOTED by calling SetCorpseDelay(timer, true)
+            float decayRate = m_ignoreCorpseDecayRatio ? 1.0f : WorldConfig.GetFloatValue(WorldCfg.RateCorpseDecayLooted);
+
             // corpse skinnable, but without skinning flag, and then skinned, corpse will despawn next update
             if (loot.loot_type == LootType.Skinning)
                 m_corpseRemoveTime = now;
@@ -3102,7 +3104,12 @@ namespace Game.Entities
 
         public ulong GetSpawnId() { return m_spawnId; }
 
-        public void SetCorpseDelay(uint delay) { m_corpseDelay = delay; }
+        public void SetCorpseDelay(uint delay, bool ignoreCorpseDecayRatio = false)
+        {
+            m_corpseDelay = delay;
+            if (ignoreCorpseDecayRatio)
+                m_ignoreCorpseDecayRatio = true;
+        }
         public uint GetCorpseDelay() { return m_corpseDelay; }
         public bool IsRacialLeader() { return GetCreatureTemplate().RacialLeader; }
         public bool IsCivilian()