[FIX] test_website: add test for 308 redirect and qs

With a 308 redirection from `/url` to `/new_url`:
Links like `/url?a=a` should be rewritten to `/new_url?a=a` and not
`/new_url?a=a&a=a`.

closes odoo/odoo#81685

Signed-off-by: Nicolas Lempereur (nle) <nle@odoo.com>