Can't retrieve openidConnect PreferredUsername from User object

[thepaperpilot]

Currently, PreferredUsername is only used as a fallback if NickName is not available. However, I'd like to access it regardless of what NickName is (or isn't) set to.

Ideally, I'd like to see User.Name be preferred_username and User.NickName be "nickname", falling back to "name", falling back to "given_name".