It's at a very simple stage for now:
- Tab control is no longer recreated when friends change, counts are
updated as bindables.
- All async logic removed temporarily.
- Sort and filtering happens in realtime without panel reload.
- Display modes removed for now. Need to think about this one a bit more,
and whether to retry the async path or look for a separate solution.
- Real time user presence is now considered. Not considered for sorting
by last visit time yet.