erp5_web: introduce translatable path.
If /help/ Web Section has translation : {'de': 'hilfe', 'fr': 'aide'}, this section can be accessible by the following path : * /de/hilfe/ * /fr/aide/ Also access to non-translated paths will be redirected like (for GET method) : * /de/help/* => /de/hilfe/* * /fr/help/* => /fr/aide/*