net/ipaddr: New port: Command-line IP address manipulation tool

ipaddr is a command-line tool for manipulating and querying IP addresses
and networks. It provides functionality similar to Python's ipaddress module
but as a standalone CLI utility.

Features include:

• IPv4 and IPv6 address normalization
• CIDR and netmask prefix notation support
• Network calculations (network, broadcast, host addressing)
• Address classification (private, loopback, multicast, etc.)
• Subnet and supernet operations
• Command chaining for complex operations
• IPv6-specific features (6to4, Teredo, zone-id)

WWW: https://github.com/astralblue/ipaddr

PR: 292621
Reported by: Eugene M. Kim <ab@astral.blue> (new maintainer)