Fix: Use SECURITY_OPEN for evaluating network protocol - #2012

Numerous fixes + enhancements in this PR:

1. correct handling of open networks
2. refactored connectedWifiStations() by removing iwconfig (deprecated)
3. sudoers fixes that prevented wpa_cli from executing commands
4. fixed handling of network indexes
5. removed stale socket in reinitializeWPA()
6. cleaned up PHP warnings with defaults in templates/wifi_stations/network.php

Tested extensively by:

1. adding networks with and without security ("open")
2. disconnecting networks (new capability)
3. deleting networks
4. switching networks (connect to other "known" network while connected)
5. verify correct state is parsed + returned with wpa_cli status

Well done!

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