First version of foreman_ipa module

We rely on other third party modules, so don't expect them to align to Foreman development with no input, we expect to remain involved if necessary to guide and add support where we need it.

I would however want to ensure we use a well-accepted and leading module if we were to pick one.  These are not modules just for use in an installer, they're intended to be used directly in Puppet too, so would want to avoid picking something obscure that would cause people conflicts.

(Other modules include @stbenjam's for client registration btw: https://forge.puppetlabs.com/stbenjam/ipaclient)