Converts ie_rsn_akm_suite values (and WPA1 hint) into a more
human readable security string such as:
WPA2-Personal, WPA3-Personal, WPA2-Personal + FT etc.
AP mode will use the same structure for its diagnostic interface
and mostly the same dictionary keys. Apart from ConnectedBss and
Address being different, the remainder are the same so the
diagnostic_station_info to DBus dictionary conversion has been made
common so both station and AP can use it to build its diagnostic
dictionaries.
With AP now getting its own diagnostic interface it made sense
to move the netdev_station_info struct definition into its own
header which eventually can be accompanied by utilities in
diagnostic.c. These utilities can then be shared with AP and
station as needed.