[IMP] auth_top, *: revamp Two-factor authentication flow

Purpose
=======

Review the UX of the 2-factor authentication flow in order to make it more clear
and easy to use.

Specifications
==============

This commit applies multiple rewording of instructions, button, etc. Tests have
been adapted accordingly.

It also adds an 'invite to use two-factor authentication' flow that will
send an email to the selected used to redirect them their account security
settings.
- If portal is not installed yet, the user is redirected to his account security
settings in backend.
- If portal is installed, the user is redirected to /my/profile if them are
portal user. Otherwise, the redirection is still done at backend side.

As the backend view of auth_totp wizard is used at frontend side, copyclipboard
widget has to be rebuilt at frontend side (click event, style etc..).

As API key section is now displayed only on debug mode, test urls have been
adapted accordingly.

Task-2487630

Part-of: odoo/odoo#71142