Move filename validation to nautilus-namecodes package

[josecelano]

The Python package nautilus-namecodes defines how the media filename format should be. Currently, it only allows getting the list of codes. We want to include in that package the filename validation which is done here.

I see at least two ways of doing it @da2ce7?

1. We create a Python API and we directly use the functions from that package. I think this should be faster because we only have to move the code to that package and define the API.
2. The interface is the console. We define new commands in the nautilus-namecodes console app to do these tasks: validate a filename, etcetera.

WHich one have you planned to use @da2ce7?

cc @yeraydavidrodriguez