ui#851 - Hide total blocked counter in bubble UI for private tabs
Refs https://gitlab.com/eyeo/adblockplus/abpui/adblockplusui/-/issues/851
- Added changes from @ThomasGreiner's original MR: https://gitlab.com/eyeo/specs/spec/-/merge_requests/357
- Added fallback for when all features are inactive and hidden (see comment https://gitlab.com/eyeo/adblockplus/abpui/adblockplusui/-/issues/851#note_423740861 for details)