ipv6: wip convert FS_HostAddr to rx_address

Change-Id: I91fde5d66526660830401be3cda87b6b935e264a
ipv6: reinstate h_ClassifyAddress; it is ipv4 only

Change-Id: I3c37672fec9842f906313d6938a254dd5bb55408
ipv6: support same rx_sockaddr for init and new service

Change-Id: I0f91e96bf4a9bb4bf5fbb47d17fd6dce0856ae8f