Add GPU passthrough fields in the UI

We should allow users to specify following fields for GPU passthrough:

isolated_gpu_pci_ids

Endpoint to use for this is system.advanced. This is a list of PCI ids which the system should not consume. Choices for this field come from "device.gpu_pci_ids_choices" endpoint.

For VMs we should add a boolean field hide_from_msr defaulting to false.

I think it would be nice if we can simplify the process in the UI as well so that users can select GPU isolation from VM section and not have to go to a different section to specify pci ids for gpu isolation.