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).
Every single roaming test had one of two problems with watching the
state change between roaming --> connected. Either the test used
wait_for_object_condition to wait for 'connected' which could allow
other states in between. Or it simply used an assert. The assert
wouldn't allow other state changes, but at the cost of potentially
failing due to IWD not having made it to the 'connected' state yet.
Now we have wait_for_object_change which takes two conditions:
initial (from_str) and expected (to_str). This API will not allow
any other conditions except these, and will wait for the expected
condition before continuing. This allows roaming test to reliably
wait for the roaming --> connected state change.