Original PR description

Steps to reproduce:
1. Install `point_of_sale`, `product_barcodelookup` and `website_sale`.
2. Open a pos session.
3. Find and click the `Create Product` button from the burger menu at the top
   right of the app.
   -> The whole app crashes because of missing dependencies.

This is because we are trying to show a form view customized by
`website_new_content_form` but the pos app is not aware of the
`new_content_form.js` asset.

The pos app doesn't need the `website_new_content_form` customization so this
commit proposes a solution to convert the `website_sale`'s product form view
to become a primary view, so that it's customization is not incorporated in other
views that inherit the base view (which in this case is the
`product.product_product_view_form_normalized`).

Additionally, we incorporate a set of tour steps to make sure the product form
view is accessible whenever system user is logged in to open the pos app.