Fix bot chest looting exploits in ICC and Halls of Stone (#1280)

- Prevent bots from looting Gunship Armory chest in ICC before the event ends (#1162)
- Fix bots being able to loot Tribunal Cache in Halls of Stone multiple times (#1200)
- Ensure bots do not attempt to loot Deathbringer's Cache in ICC before it is available

Three chests (Gunship Armory, Tribunal Cache, Deathbringer's Cache) were tested and now behave as expected: bots will not approach or attempt to loot chests while they are unlootable, even if players move close to them.

Closes #1162, #1200

src/LootObjectStack.cpp

@@ -85,7 +85,7 @@ void LootObject::Refresh(Player* bot, ObjectGuid lootGUID)
         bool hasAnyQuestItems = false;
 
         GameObjectQuestItemList const* items = sObjectMgr->GetGameObjectQuestItemList(go->GetEntry());
-        for (int i = 0; i < MAX_GAMEOBJECT_QUEST_ITEMS; i++)
+        for (size_t i = 0; i < MAX_GAMEOBJECT_QUEST_ITEMS; i++)
         {
             if (!items || i >= items->size())
                 break;
@@ -297,6 +297,11 @@ bool LootObject::IsLootPossible(Player* bot)
             return false;
     }
 
+    // Prevent bot from running to chests that are unlootable (e.g. Gunship Armory before completing the event)
+    GameObject* go = botAI->GetGameObject(guid);
+    if (go && go->HasFlag(GAMEOBJECT_FLAGS, GO_FLAG_INTERACT_COND | GO_FLAG_NOT_SELECTABLE)) 
+        return false;
+
     if (skillId == SKILL_NONE)
         return true;