Merge pull request #1400 from johnelse/gpu-group-methods

Implement new GPU_group methods
CP-5840: Populate new PGPU fields when upgrading the DB

Signed-off-by: John Else <john.else@citrix.com>
CP-5840: Set VGPU types when upgrading the DB.

All existing VGPUs will be given the special "passthrough" VGPU type.

Signed-off-by: John Else <john.else@citrix.com>
CP-5840: Bump DB schema so that the upgrade runs

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