Add VGPU.type field

Signed-off-by: John Else <john.else@citrix.com>
Add a record type for VGPU_type to the CLI

Signed-off-by: John Else <john.else@citrix.com>
VGPU.type should default to Ref.null

Signed-off-by: John Else <john.else@citrix.com>
Add VGPU.type to the CLI

Signed-off-by: John Else <john.else@citrix.com>
Add VGPU feature flag

Signed-off-by: John Else <john.else@citrix.com>
Add method GPU_group.get_allowed_VGPU_types

Signed-off-by: John Else <john.else@citrix.com>
Add new GPU_group fields to the CLI

Signed-off-by: John Else <john.else@citrix.com>