[18.0][IMP] use commercial_partner_id iso parent_id

[remi-filament]

As per #49 (comment)

It seems more appropriate to make use of commercial_partner_id rather than parent_id.
Also a number of times parent_id was used to make sure the partner was not a contact, where checking is_company seems more accurate.

Commercial_partner_id is computed as follow (see https://github.com/odoo/odoo/blob/fc7bd92cc52f366a0d8730bca066b757aefe870c/odoo/addons/base/models/res_partner.py#L450) :

• if partner is a company or has no parent : commercial_partner_id = partner
• else : commercial_partner_id = partner.parent_id.commercial_partner_id

This allows for 2 things which are not covered by simply using parent_id :

• Have multiple levels of partners : commercial_partner_id is the higher level partner (or the first upper level which is a company)
• Use partner itself if it is a company (which is child of another company) : in this case, I think it makes sense to use the company itself rather than its parent

[ak-git-bot]

Hi @alexis-via,
some modules you are maintaining are being modified, check this out!