USB4: generation attribute for the manager
Now that we have the
Generation (D-Bus) attribute for each device, we should "proxy" the generation of the host to the manager, so clients (e.g. GNOME Settings), don't need to iterate devices to find out if the host is Thunderbolt X or USB4.
Implementation wise, the approach would be to persist the host device, i.e. store it, and in the manager do something analogous to the
SecurityLevel, every time a host controller is appearing, populate the
Manager.Generation attribute, but only if it is not yet populated.