New port: misc/liblxi

liblxi is an open source software library which offers a simple API for
communicating with LXI compatible instruments. The API allows applications
to discover instruments on your network, send SCPI commands, and receive
responses.

WWW: https://lxi-tools.github.io

PR: 224713, D13685
Submitted by: Dmitri Goutnik <dg@syrec.org>