Fixed an issue where subscription line subtotals were displaying incomplete tax information on the customer portal. When subscriptions contained sections, the subtotal now correctly shows both tax-included and tax-excluded amounts, providing customers with accurate pricing details.

When subscription lines had sections, subtotal
was showing only value without tax. Now it
shows both tax included and excluded subtotal.

task-3218286

Forward-Port-Of: odoo/enterprise#53219
Forward-Port-Of: odoo/enterprise#49124