Missing parent namespace when generating dependant ASN.1

[Thiesius]

When generating code for ITS-Container.asn and CAM-PDU-Descriptions as per "CAM EN 302 637-2" the generated code cannot be compiled.

Few types which are referencing from CAM to ITS are missing ITS_Container namespace. Managed to hotfix that by modifying
type_as_string to make it find the module where the type occurs and then prefix it with fast_ber and module_name.