Add support for using login+password+yubikey otp when logging in
The regular web client only has support for two input fields in the login form. Thus, when using YubiKey the username was skipped to instead use one-time-password generated by the YubiKey.
When creating new client applications it is possible to design the login form differently and require 3 input fields:
- YubiKey OTP
The extra information can be sent with the
NOTE! This will not change the behaviour in the regular web client, only in clients created specifically with this in mind (see #891).