Rearchitect the front-end of the app again

[TolikPylypchuk]

FluentUI components from Microsoft are just not great to work with, as it turns out, and they lack a lot of features. Also, I though I would use elements of FAST (like design tokens), but they seem to be very inconvenient to actually use in the FluentUI library.

I'll migrate the entire front-end to MudBlazor and will restyle it to look a little less than pure material UI (hopefully, I will be able to do that).