[FR] Two-factor authentication

[gammexane]

Please describe the problem / need you are trying to solve.
User and password is not enough these days for very well known security reasons, I would love to have 2FA or even better U2F.

Describe the feature or the improvement you'd like and what are you trying to achieve.
After the user and pass, Taiga should request a Two-Factor authentication (2FA or U2F)

Describe alternatives you've considered
N/A