Adds a test to be sure `product.template` can be create with a
responsible when:
- The product has no `company_id` (the responsible must belong to the
user's company in this case).
- The product `company_id` is one of the companies of its responsible.
And to be sure that we can't create a `product.template` if its
responsible doesn't belong the product's company.
closesodoo/odoo#37362
Signed-off-by: Simon Lejeune (sle) <sle@openerp.com>