Add v2 config format parsing

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