Added support for namespaced API names.

This PR adds support for namespaced API names. An API may have a namespaced name if the module is loaded through a PSR-4 autoloader. 

For example the API may be namespaced: "Company\\Project1Api". If that's the case, the zf-apigility-documentation module doesn't handle the API name properly and among other issues this causes navigating to the API's documentation impossible.