Add MVVM Format

[Lfdstudios]

I've been struggling for months now trying to get this working correctly with MVVM format. I want it to try to acquire a token AND display usercontext automatically but that isn't possible in this format. It is very unclear about how to use IAuthService.

If you could make it in MVVM with ViewModelBase acquiring token/usercontext and a mainpage showing how to display this context that would be very helpful.