GSDML DTM: Support for shared device feature required

GSDML DTM (PROFINET Generic Device DTM): Support for shared device feature required:
The GSDML DTM follows the GSDML spec and thus is sticked to the "fixedInSlot" definitions there, not knowing/considering shared device configuration requirements.
A submodule in a shared device can be configured either for one controller or another.
In case of "FixedInSlot" submodules (PDEV too), current implementation of the GSDML DTM doesn't allow removing/disabling/marking as unused of such submodules.