Add tests of the v2 config format parsing

Signed-off-by: John Else <john.else@citrix.com>
CP-8359: Add check for subsystem device IDs

If the config file specifies a required subsystem device ID for a device
type, take this into account when constructing the list of metrics
required for a device.

Signed-off-by: John Else <john.else@citrix.com>
nvml: Load symbol nvmlDeviceGetPciInfo_v2

nvmlDeviceGetPciInfo is aliased to nvmlDeviceGetPciInfo_v2 in nvml.h,
however because we are here loading the symbol dynamically by its name
the alias does not take effect. To work around this, we load the symbol
nvmlDeviceGetPciInfo_v2 explicitly.

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