Bump the API version

Signed-off-by: John Else <john.else@citrix.com>
Add lifecycle field to GPU_group.allocation_algorithm parameter

Signed-off-by: John Else <john.else@citrix.com>
Add datamodel version for vGPU productisation

Signed-off-by: John Else <john.else@citrix.com>
CP-6257: Convert a couple of getter methods to fields

GPU_group.supported_VGPU_types and GPU_group.enabled_VGPU_types are now
fields, rather than values computed on demand.

Signed-off-by: John Else <john.else@citrix.com>
CP-6257: These fields are no longer expensive

Signed-off-by: John Else <john.else@citrix.com>
CP-6257: Update group's enabled VGPU types after changing them on a PGPU

Signed-off-by: John Else <john.else@citrix.com>
CP-6257: Expose new functions to the API for internal use

Signed-off-by: John Else <john.else@citrix.com>
CP-6257: Update new fields when moving PGPUs between groups

Signed-off-by: John Else <john.else@citrix.com>
CP-6257: Update GPU_group.[enabled|supported]_VGPU_types at startup

If, when xapi starts up, the Dbsync code finds that new GPUs have
arrived or old GPUs have gone away, we need to update the supported and
enabled VGPU types of the groups containing those GPUs.

The update requests are sent to the master as an API call, for
efficiency.

Signed-off-by: John Else <john.else@citrix.com>
CP-6257: Implement PGPU.supported_VGPU_max_capacities

Signed-off-by: John Else <john.else@citrix.com>
Merge pull request #1508 from johnelse/vgpu-extra-api

VGPU API changes for XenCenter