Core/SmartScript: create SMART_ACTION_SET_CORPSE_DELAY

by Vincent-Michael, updates #16488

New smart action SMART_ACTION_SET_CORPSE_DELAY:
- Allows setting the delay of corpse decay time in SmartScript

(PR opened on request from Rushor)
Constructive feedback is welcome.

src/server/game/AI/SmartScripts/SmartScript.cpp

@@ -2330,6 +2330,21 @@ void SmartScript::ProcessAction(SmartScriptHolder& e, Unit* unit, uint32 var0, u
                 break;
             }
         }
+        case SMART_ACTION_SET_CORPSE_DELAY:
+        {
+            ObjectList* targets = GetTargets(e, unit);
+            if (!targets)
+                break;
+
+            for (ObjectList::const_iterator itr = targets->begin(); itr != targets->end(); ++itr)
+            {
+                if (IsCreature(*itr))
+                    (*itr)->ToCreature()->SetCorpseDelay(e.action.corpseDelay.timer);
+            }
+
+            delete targets;
+            break;
+        }
         default:
             TC_LOG_ERROR("sql.sql", "SmartScript::ProcessAction: Entry %d SourceType %u, Event %u, Unhandled Action type %u", e.entryOrGuid, e.GetScriptType(), e.event_id, e.GetActionType());
             break;