devel/sv: Semantic versioning in c99

This is free and unencumbered software released into the public domain.
This package installs a C language library implementing semantic
versioning for the C language.

WWW: https://github.com/uael/sv/

This port also builds with cmake, but as it is a prerequisite for an
upcoming port of the xmake build system, I did not want to make the
dependency chain longer than it needs to be.

PR: 284724
Co-authored-by: Huan Zhou <pericycle.cc@gmail.com>