This commit enables eCommerce customers to pay with the express payment
methods Apple Pay and Google Pay from the cart page.
For the moment, only Stripe supports this additional feature but it
was designed to make it easy to implement with a new provider.
task-2754209
closesodoo/odoo#88374
Related: odoo/enterprise#29915
Related: odoo/documentation#2392
Signed-off-by: Antoine Vandevenne (anv) <anv@odoo.com>