This adds the basic mechanism for running through network selection:
scan, ANQP fetch, network selection, and connection. Actual rules for
network selection and the creation of the network block are still
missing, but will be added in separate commits.
Add mechanism for using GAS/ANQP to query Interworking related
information from APs. The received information is stored in the BSS
table and can be viewed with ctrl_iface BSS command.
New ctrl_iface command ANQP_GET can be used to fetch ANQP elements from
a specific AP. Additional commands FETCH_ANQP and STOP_FETCH_ANQP can be
used to initiate and stop an iteration through all APs in the BSS table
that indicate support Interworking to fetch ANQP elements from them.