Core/Script: add script hook to allow overriding of a vehicle passenger's exit position

Port From (https://github.com/TrinityCore/TrinityCore/commit/1edd93bc0c443cdabc104af9f440e07b6d473a08)

Source/Game/Scripting/CoreScripts.cs

@@ -303,6 +303,9 @@ namespace Game.Scripting
 
         // Called when Spell Damage is being Dealt
         public virtual void ModifySpellDamageTaken(Unit target, Unit attacker, ref int damage, SpellInfo spellInfo) { }
+
+        // Called when an unit exits a vehicle
+        public virtual void ModifyVehiclePassengerExitPos(Unit passenger, Vehicle vehicle, Position pos) { }
     }
 
     public class GenericCreatureScript<AI> : CreatureScript where AI : CreatureAI

Source/Game/Scripting/ScriptManager.cs

@@ -1100,6 +1100,10 @@ namespace Game.Scripting
             ForEach<UnitScript>(p => p.ModifySpellDamageTaken(target, attacker, ref dmg, spellInfo));
             damage = dmg;
         }
+        public void ModifyVehiclePassengerExitPos(Unit passenger, Vehicle vehicle, Position pos)
+        {
+            ForEach<UnitScript>(p => p.ModifyVehiclePassengerExitPos(passenger, vehicle, pos));
+        }
 
         // AreaTriggerEntityScript
         public AreaTriggerAI GetAreaTriggerAI(AreaTrigger areaTrigger)