devel/rubygem-puppet-modulebuilder: New port

The purpose of this tool is to take a given local module directory and compile
it into a .tar file, known as the tarball, that can then be installed directly
by Puppet on a target machine or uploaded onto the Puppet Forge so that it can
be accessed publicly.

As part of this process any non-deliverable aspects of the module, parts of it
related to the modules development or testing for example, are stripped away
leaving only the documentation and the puppet/ruby code that is needed for the
module to function.

The parts of the module to be excluded are defined in a .pdkignore, .pmtignore
or .gitignore file with the first one to be found in this given order being
used. Any directories or files that are listed in the ignore file are then
excluded, allowing the user to customize what is and what is not excluded.

It should have been committed prior to the update of devel/rubygem-pdk
in 2891c0317f0e82c88fa061df625a5ffae826c6be but slipped through.

PR: 281772
Reported by: cperciva, meta, Trond.Endrestol@ximalas.info