Handle authorization or enrollment of parent devices

Show the parents of a target (i.e. the devices that the target is connected via) in the device dialog. On "Authorize & Connect" also enroll/authorize any parents that need to be authorized/enrolled as well.

Can be tested via bolt-mock:

sudo bolt-mock
controller new

launch GNOME Settings and also disable authorization in the panel

device new 0-0 cable
device new 0-100 dock
device new 0-101 gpu

re-enable authorization in the panel. Now the parents should be visible, have a warning icon. Authorization should work and parents should be authorized (NB: the doc of gtk_container_get_children does not say anything about the order, but I should be the correct one).

NB: there is a not handled corner case: if a parent is enrolled but not authorized and the target is not enrolled, we are in trouble and cannot do the right thing. I have an idea to fix that but I might not make it before the UI freeze.

Update: I added a new function to BoltClient that can handle a mix of Authroize and Enroll operations so that corner should be fixed.

Closes #128 (closed)