Advertise devices shared between nodes

While the driver currently advertises Node-local "GPU" devices, it would be great also to show what devices shared between Nodes look like and how to claim those. e.g. NVIDIA IMEX channels: https://github.com/NVIDIA/k8s-dra-driver/blob/32805fec62d6b3269e75ddb0eddeaa5c4d214564/demo/specs/quickstart/imex-test1.yaml