www/wp-cli: New port: Command line interface for WordPress

WP-CLI is the command-line interface for WordPress.
You can update plugins, configure multisite installations and much more,
without using a web browser.

Co-authored-by: Vladimir Druzenko <vvd@FreeBSD.org>
Co-authored-by: takefu@airport.fm
Co-authored-by: avkarenow@o2.pl

PR: 257679