This test was just piping the PSK files into /tmp/iwd/ssidCCMP.psk
which is a bit fragile if the storage dir was ever to change. Instead
use copy_to_storage and the 'name' keyword to copy the file.
This changes all tests to use the default get_ordered_network behavior
rather than some custom or incorrect logic. Any use of
scan_if_needed=True has been removed since this is now the default.
Also any explicit scanning has been removed for tests which do not
require it (where the default behavior is good enough).
Many tests waited on the network object 'connected' property after
issuing a Connect command. This is not correct as 'connected' is
set quite early in the connection process. The correct way of doing
this is waiting for the device state to change to connected.
This common code was replaced, hopefully putting to rest any random
failures that happen occasionally.
