The interface name shall start with the hostname of the host it is
associated to.

Note that this is only enforced via the UI (from which most users will interact),
not from the API.

Fixes INFRA-195

Use endpoint argument to avoid collision with flask-admin Network

- disable item field for virtual hosts
- pre-fill interface name with hostname

- Main blueprint used to declare custom views for all blueprints.
(keep inventory blueprint cleaner)
- Add url_prefix to each blueprint