Summary
=======
- [x] Changes endpoint ActivityCenterNotificationsBy to support fetching
multiple types of notification in a single query.
- [x] Adds endpoint UnreadAndAcceptedActivityCenterNotificationsCount to
allow the mobile client to fetch the count of unread & accepted
notifications.
- [x] Add `golangci-lint` to Nix shell. This was possible since PR
https://github.com/status-im/status-go/pull/3087 was merged.
Notes
=====
- If you'd like to understand why these changes are needed, please see
the mobile PR https://github.com/status-im/status-mobile/pull/14785,
or issue https://github.com/status-im/status-mobile/issues/14712
- All changes should be completely backwards compatible, and there
should be no impact for the desktop app.
- The mobile client has been already tested using this branch.
e40cbfc28f