Core/Script: add script hook to allow overriding of a vehicle passenger's exit position (#23322)

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

* Allow to change orientation, and fix nopch.

* Keep original orientation, thanks jackpoz!

* Update Unit.cpp

Code cleanup

* Update Unit.cpp

(cherry picked from commit 88c6c61b95ac2b2f911b519136770479d31de27d)

src/server/game/Scripting/ScriptMgr.cpp

@@ -2326,6 +2326,11 @@ void ScriptMgr::OnQuestObjectiveChange(Player* player, Quest const* quest, Quest
     tmpscript->OnQuestObjectiveChange(player, quest, objective, oldAmount, newAmount);
 }
 
+void ScriptMgr::ModifyVehiclePassengerExitPos(Unit* passenger, Vehicle* vehicle, Position& pos)
+{
+    FOREACH_SCRIPT(UnitScript)->ModifyVehiclePassengerExitPos(passenger, vehicle, pos);
+}
+
 SpellScriptLoader::SpellScriptLoader(char const* name)
     : ScriptObject(name)
 {