This merge request should be the final answer to the basic question of detecting interfaces (at least for now, given the current state of hardware & kernel). All internal HW (PCI cards - WIFI, LTE), ethernets should be recognized, as well as external (USB eth & wifi cards). It doesn't rely on fixed interface names anymore.
Interfaces are detected dynamically and their type is decided based on the bus they reside on. All interfaces should be detected, no interface should pass unnoticed (at least a warning should be printed).
Also, tests are changed, test roots are now tar files. Previously used tests root with thousands of files can and will be deleted, I just don't want to include deleting them into this merge request - to keep it readable.