Fixes #4515 - Add support for dynamic bindings

This PR mutually dependant with https://github.com/theforeman/foreman/pull/1265

With this update Apipie can handle both the Foreman and the Katello APIs. It
- fixes inheritance and versioning of resource descriptions
- adds correct api prefix to Katello resource descriptions

It is necessary to sync the merge of both PRs. I'm not sure if it is still possible to generate katello_api (static bindings) with this new apipie setup. I'm also not aware, what other parts of Katello infrastructure  depends on the bindings (installer, orchestration?) and if it is possible/wanted to convert them to the new bindings. But I can help with the conversion.