Allow stateful Auth

This patch not change current out of the box behavior, it just allow Apigility users opt to stateful Auth.

A way to do that is providing a replacement to the 'ZF\MvcAuth\Authentication' service's factory (`AuthenticationServiceFactory`) to use as storage something different than `NonPersistent`.

Stateful auth is conceptually against RESTful principles, but come in handy in some environments. That is why I think we should allow Apigility users decide about.