Fritzbox integration: Expose IPv6 address and prefix information

Hello,

currently the Fritzbox integration only exposes the IPv4 address of the WAN interface. The integration appears to be based on the Fritzconnection python library, which from what I can tell has support for the IPv6 stuff (see: fritzconnection/fritzstatus.py at master · kbr/fritzconnection (github.com) ).

It’d be nice if the IPv6 WAN address and the prefix (I guess including subnet bits, as string in the prefix/bits format, e.g. 2a02:dead:beef::/64) would be exposed as sensors, too.

Thanks.