Connections Manager

[MathiasKoch]

It would be nice if we could add some kind of connections manager around the config slots in UWSC.

It should be able to do basics of:

• Add, list, modify & delete stored wifi connections (All parameters of UWSC)
• Activate & deactivate stored wifi connections (UWSCA)
• Rank known connections to return best available connection (See https://askubuntu.com/questions/1348220/how-does-networkmanager-choose-which-wifi-network-to-connect-to-when-muliple-are & https://github.com/digsrc/wpa_supplicant/blob/515eb37dd1df3f4a05fc2a31c265db6358301988/wpa_supplicant/scan.c#L1658 for inspiration on how this is handled in wpa_supplicant)

[MathiasKoch]

Fixed for now by #46