When some module used 'freeipa/navigation' it pulled the entire Web UI
because navigation depended on app.
This patch splits the app into two modules: app and app_container.
App specifies the entities which are part of final application.
app_container module represents the application boot classes. Navigation
now depends on app_container.
Reviewed-By: Adam Misnyovszki <amisnyov@redhat.com>