This removes all the duplicated code where the interfaces are iterated
and the radio/hostapd instances are created. Instead the two new APIs
are used to get each instance, e.g.:
hapd = HostapdCLI(config='ssid.conf')
radio = hwsim.get_radio('radX')
In the tests that only want to iterate over the hostapd interfaces,
simplify the pattern of walking through the whole wiphy_map tree by
instead using the hostapd_map variable which is already filtered to only
contain hostapd interfaces.
This is a VERY simple test for HT/VHT. Since there are so many potential
options in the IE this really just tests that drops in RSSI will cause
IWD to choose a different BSS, even if that means choosing HT over VHT,
or even basic rates over HT/VHT.
