[ADD] Migrated <mass_editing> for Odoo

Odoo again doesn't have an homogeneus rule for naming this, so there are some folders on plural and some on singular. `data` and `demo` are plural themself, so I prefer to make `models` and `views` also plural. About `_view` suffix, it's not that bad, if you make a file search or you make specific files for menus.