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

Signed-off-by: John Else <john.else@citrix.com>
CP-5840: Make use of re-usable Pci_db optimisation

Signed-off-by: Si Beaumont <simon.beaumont@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>
Merge pull request #1406 from simonjbeaumont/cp-5840

Database upgrade logic for vGPU support