Purpose
=======
The flow where we copy / paste the authorization code will be
depreciated. Because of that, we know use the newest authentication
system which use redirect URI.
Technical
=========
Now, the user is redirected to an Odoo endpoint "google_gmail/confirm"
and the access token / refresh token are automatically fetched.
Documentation
https://developers.google.com/identity/protocols/oauth2/native-app
Task-2852560
closesodoo/odoo#94476
X-original-commit: 69bd9bc6b36fdd55e8e859667bcddddad6db7d06
Signed-off-by: Thibault Delavallee (tde) <tde@openerp.com>
