CA-127324: Catch error and continue if we fail to lookup a vendor or device ID

This allows a pGPU to be created even if pci.ids is missing one of those
fields for a device.

Signed-off-by: John Else <john.else@citrix.com>
CA-127325: Don't try to read subvendor/subdevice IDs for physical devices

We don't need these IDs, and some devices don't implement them (in which
case the old sscanf fails).

Signed-off-by: John Else <john.else@citrix.com>
Move filter_chars to parse_lspci_line

Signed-off-by: John Else <john.else@citrix.com>
Add tests for parse_lspci_line

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