FIDO2 pin support / feature-parity with google play services

[Yannik]

Is your feature request related to a problem? Please describe. Google play services now support using FIDO2 with pin: https://www.rprna.com/news/google-play-system-fido2-pin-support/

It would be great to have this supported in microg too.

Describe the solution you'd like

Something similar to the flow with google play services:

[Yannik]

There is a PR for this here: https://github.com/microg/GmsCore/pull/2194