gh-111442: Use first_address and last_address internally, and refer to them in IPv4 and IPv6 networks as network_address, subnet_router_anycast or broadcast_address only if appropriate to the address family.

gh-111442: Use first_address and last_address internally, and refer to them in IPv4 and IPv6 networks as network_address, subnet_router_anycast or broadcast_address only if appropriate to the address family. #6012