support wireless-tools when nmcli is not available

[sevenbitbyte]

Basic debian systems (and likely more) ship without nmcli and instead use /etc/network/interfaces.d/ & wpa_supplicant to configure managed mode wifi. These non-monitor-mode interfaces can still be used for general AP scanning typically even when the interfaces is associated to an AP.

When in this mode the most supportable solution seems to be to parse the out put from iw scan directly. When run with sudo a real time scan can be triggered. There may be some caching still going on.