Allow multiple RoadNetwork LogicFile(s)

Describe the feature

The current OpenSCENARIO 1.2 standard XSD allows only one LogicFile entry for the road network description. For special use cases like running NDS or other proprietary maps as part of the simulation it would be useful to reference the "secondary" maps alongside the primary map.

Describe the solution you would like

Therefore, I propose to allow referencing more than one LogicFile and change the XSD accordingly.

Example:

    <RoadNetwork>
        <LogicFile filepath="../Track/my_map.xodr"/>
	<SceneGraphFile filepath="../Track/GLB/my_map.glb"/>
        <LogicFile filepath="../Track/my_map.format_x"/>
	<LogicFile filepath="../Track/my_map.format_y"/>
    </RoadNetwork>

Describe alternatives you have considered

In case it is a problem to have to elements with the same name it could be called LogicFile and LogicFileSecondary.

Describe the backwards compatibility

It should be possible to ensure backwards compatibility since nothing old would be removed or renamed.

Additional context

Component testing, virtual ECUs