Planning for release 1.2.0 - JupyterHub 4 compatibility

[consideRatio]

I'd like to see a new release cut with the JupyterHub 4 compatibility added via #236 and #239, for z2jh 3.0.0 and tljh 1.0.0 releases.

Not blocking, but needs a review

• Fix broken implementation of import_from_firstuse #221
• Numerous Improvements for Two Factor Authentication #223

[lambdaTotoro]

I have a move coming up and will not have spare brain power available until mid June at the earliest. I am happy with you using your own best judgement, though. Feel free to go ahead as needed.