www/p5-Dancer2-Plugin-FormValidator: Add new port

This is micro-framework that provides validation in your Dancer2
application. It consists of dsl's keywords and a set of agreements.
It has a set of built-in validators that can be extended by
compatible modules (extensions). Also proved runtime switching
between languages, so you can show proper error messages to users.

WWW: https://metacpan.org/pod/Dancer2::Plugin::FormValidator