Core/ObjectMgr: Refactor arena team related functions into dedicated class

src/server/game/World/World.cpp

@@ -37,6 +37,7 @@
 #include "AchievementMgr.h"
 #include "AuctionHouseMgr.h"
 #include "ObjectMgr.h"
+#include "ArenaTeamMgr.h"
 #include "TicketMgr.h"
 #include "CreatureEventAIMgr.h"
 #include "SpellMgr.h"
@@ -1518,7 +1519,7 @@ void World::SetInitialWorldSettings()
     sObjectMgr->LoadGuilds();
 
     sLog->outString("Loading ArenaTeams...");
-    sObjectMgr->LoadArenaTeams();
+    sArenaTeamMgr->LoadArenaTeams();
 
     sLog->outString("Loading Groups...");
     sObjectMgr->LoadGroups();