Port the getaddrinfo(1) utility from NetBSD

Submitted by: Lohith Bellad <lohithbsd@gmail.com>
Reviewed by: hiren (earlier rev), ae
Obtained from: NetBSD
MFC after: 1 week
Relnotes: yes
Sponsored by: Dell EMC
Differential Revision: https://reviews.freebsd.org/D9365