[FIX] payment: float consistency enforcement in access_token generation

Steps to reproduce:
- install sales, ecommerce and payment_authorize
- setup authorize.net (test mode)
- go to sales and select the quotation S00007 (demo data) or create a quotation
with multiple items that add up to a float
- select action > generate a payment link > go to the link > select pay with authorize
- you are redirected to authorize.net use 4111 1111 1111 1111 as card number and 1223
as expiration date > pay
- you are redirected to the odoo payment process page
- wait for the result

Previous behavior:
the user is returned to a 404 error page but the payment went trough

Current behavior:
access_token generation is consistent and will not fail because of
float representation
the user is returned to the "payment confirmed" page

WARNINGS:
- watching the values in vscode prevents bug reproduction
- when setting up authorize.net, do not forget to add your test url to
the account's allowed return urls
- use https for authorize.net connection

opw-2223135

closes odoo/odoo#50577

Signed-off-by: mightyjol <jhk-odoo@users.noreply.github.com>