Core/Battlefields: Refactor Battlefield creation to be linked to host map creation instead of having globally accessible objects

Port From (https://github.com/TrinityCore/TrinityCore/commit/073a036d84365dae60a70064eb67e68f0447bd72)

Source/Game/Scripting/CoreScripts.cs

@@ -443,7 +443,7 @@ namespace Game.Scripting
 
         public override bool IsDatabaseBound() { return true; }
 
-        public virtual BattleField GetBattlefield() { return null; }
+        public virtual BattleField GetBattlefield(Map map) { return null; }
     }
     
     public class BattlegroundScript : ScriptObject

Source/Game/Scripting/ScriptManager.cs

@@ -715,9 +715,9 @@ namespace Game.Scripting
         }
 
         //BattlefieldScript
-        public BattleField CreateBattlefield(uint scriptId)
+        public BattleField CreateBattlefield(uint scriptId, Map map)
         {
-            return RunScriptRet<BattlefieldScript, BattleField>(p => p.GetBattlefield(), scriptId, null);
+            return RunScriptRet<BattlefieldScript, BattleField>(p => p.GetBattlefield(map), scriptId, null);
         }
 
         //BattlegroundScript