Support multiple catalog directories

To our understanding OpenSCENARIO 1.2 and 1.3 does only support having catalog of specific type (e.g. Vehicle) in ONE directory.

https://www.asam.net/static_downloads/ASAM_OpenSCENARIO_V1.2.0_Model_Documentation/modelDocumentation/content/VehicleCatalogLocation.html

It would be useful to be able to have catalogs in multiple file directory locations. I.e. change the line:

directory	Directory	1..1	XSDelement	All catalogs files in this directory must be evaluated.

to:

directory	Directory	1..*	XSDelement	All catalogs files in this directory must be evaluated.