Introduce a new class to manage inputs, `InputManger` and move the
code to map inputs from the `Input` here. The main insight of why
the logic should be place here is that certain information is needed
to map inputs, independently of specific type: the path to the input
directory, `root`, the store API, `storeapi` and the service manager
instance to start the actual service. Instead of passing all this
information again and again to the `Input` class, we now have a
specialized (service) manager class for inputs that has all the
needed information all the time.