Sale Coupons Rewards from domain

This module extends coupon programs to support a reward type called 'free product domain'. When a customer's order contains products that match the domain defined in the coupon program, Odoo automatically adds new order lines for the free products, each with a 100% discount.

• The reward lines are created for each valid product from the domain, with quantity calculated based on the ordered quantity and the program's minimum quantity rule. If the program has a maximum quantity for reward products, that limit is applied.
• The module ensures that only products from the order that match the domain are considered for the reward. If the program has a strict per-product limit, it checks that each product meets both the minimum quantity and minimum amount before being eligible.
• When promotions are updated or removed, the module correctly removes invalid reward lines and expires related coupons, while preserving valid free product lines.
• The order count on the coupon program is computed based on the linked order lines, and the 'Sales Orders' button on the program shows only orders that used that program.
• This functionality is integrated into the sale order workflow, affecting sale.order, sale.order.line, and coupon.program models.