Improve product form with no template
Following the discussion on https://discuss.tryton.org/t/merge-products-variants-into-one-database-table-one-view-one-list/2241
One point is that when trying to create a product from an operational document (like sale line), the form is confusing because a template must be set instead of filling the read-only fields "inherited" (which can confused the user).
I propose to hide those read-only fields until a template is selected.