RFC: Inventory call

[christoph-zededa]

add inventory message for EVE to upload to controller

[christoph-zededa]

I also thought about doing something like:

message PCIDevice {
        optional PCIDevice parent_pci_device = 1;
        string driver = 2;
        PCIAddress address = 3;
...
}

but IMO that makes the coupling too tight.

[christoph-zededa]

Still lots of things are missing:

• network devices
• disks
• ...