Incorrect Handling of Default Orientation in LanePosition

According to the OpenSCENARIO definition: The Orientation attribute could be missing in the scenario definition and should default to Heading = Pitch = Roll = 0 as relative reference (https://publications.pages.asam.net/standards/ASAM_OpenSCENARIO/ASAM_OpenSCENARIO_XML/latest/generated/content/LanePosition.html).

However, in the code, orientation_ptr will be nullptr if Orientation is missing in the scenario file and the case is not correctly handled.

(https://gitlab.eclipse.org/eclipse/openpass/openscenario1_engine/-/blob/main/engine/src/Conversion/OscToMantle/ConvertScenarioPosition.cpp?ref_type=heads#L34)

Example:

It is not a major issue, but it can cause some entities' pose to be handled incorrectly if the definition of Orientation is missing.