Changes a supplier branch. Send any of the fields accepted by the create endpoint inside a
supplier_branch object; fields you leave out are unchanged.

To change the price list, send supplier_products_attributes. Include an entry's id to update
it, leave id out to add a product, and add _destroy: true to an entry with an id to remove
it. Every entry must include its product_id, even when removing it; entries without one are
ignored. Entries you don't send are left as they are.

The token's role must be owner or admin.