Core/GameObject: regenerate GO loot if respawn time passed since last loot generation time and not all items were taken (#19101)

src/server/game/Entities/GameObject/GameObject.h

@@ -801,6 +801,8 @@ class TC_GAME_API GameObject : public WorldObject, public GridObject<GameObject>
         void AddLootMode(uint16 lootMode) { m_LootMode |= lootMode; }
         void RemoveLootMode(uint16 lootMode) { m_LootMode &= ~lootMode; }
         void ResetLootMode() { m_LootMode = LOOT_MODE_DEFAULT; }
+        void SetLootGenerationTime() { m_lootGenerationTime = time(nullptr); }
+        uint32 GetLootGenerationTime() const { return m_lootGenerationTime; }
 
         void AddToSkillupList(ObjectGuid::LowType PlayerGuidLow) { m_SkillupList.push_back(PlayerGuidLow); }
         bool IsInSkillupList(ObjectGuid::LowType PlayerGuidLow) const
@@ -941,6 +943,7 @@ class TC_GAME_API GameObject : public WorldObject, public GridObject<GameObject>
         ObjectGuid m_lootRecipient;
         uint32 m_lootRecipientGroup;
         uint16 m_LootMode;                                  // bitmask, default LOOT_MODE_DEFAULT, determines what loot will be lootable
+        uint32 m_lootGenerationTime;
 
         ObjectGuid m_linkedTrap;