This commit partially reverts 5b4f7c13 where `fields_view.fields`
had been replaced by `fields`, which could have been set to all
fields in the model.

This modification can sometimes lead to a problem, during the
fields value transformation. The ID, which wasn't given previously
is now parsed. When creating a new record, the field ID is not an
integer but a string (representing the virtual ID). If the field
is in the arch, it will be postprocessed
(see https://github.com/odoo/odoo/blob/saas-11/addons/web/static/src/js/framework/data_manager.js#L201)
and its type will become `id`. As this postprocessing is not done
if the field in the view, the parsing was on the original type
(integer) and not the special id type.