Any test using assertTrue(hostapd.list_sta()) improperly has been
replaced with wait_for_event(). There were a few places where this
was actually ok (i.e. IWD is already connected) but most needed to
be changed since the check was just after IWD connected and hostapd's
list_sta() API may not return a fully updated list.
All tests which could avoid calling scan() directly have been
changed to use the 'full_scan' argument to get_ordered_network.
This was done because of unreliable scanning behavior on slower
systems, like VMs. If we get unlucky with the scheduler some beacons
are not received in time and in turn scan results are missing.
Using full_scan=True works around this issue by repeatedly scanning
until the SSID is found.
