Set scenario definition pointer within the ValidateScenario

For Map Injection mechanism, simulator needs to get "full map path" from the ScenarioEngine. We are dong it by calling GetScenarioInfo function and then retrieving the full_map_path property from the ´additional_information´. However, in case of OpenScenarioEngine, this property cannot be set unless ´scenario_data_ptr_´ is set.

In this PR, we propose to call ´SetScenarioDefinitionPtr()` from within ´ValidateScenario´ function so that the OpenScenarioEngine is ready to provide the ´full_map_path´. Please note that we cannot fully initialize Init() before we get the ´full_map_path´ because of cyclic dependency on MapLoder.