If a beacon is lost testAP will fail since it did not utilize any
rescanning logic. Now it can use this feature by passing full_scan.
This is required since IWD APs are not known to test-runner like
hostapd APs are.
[General].APRange is now [IPv4].APAddressPool and the netmask is changed
from 23 to 27 bits to make the test correctly assert that only two
default-sized subnets are allowed by IWD simultaneously (default has
changed from 24 to 28 bits)
The existing AP tests needed to be modified to start IWD from
python since the DHCP test uses a different main.conf.
Also removed some stale hw.conf options that are no longer used.
