refs https://github.com/TryGhost/Team/issues/3010
- Having all possible values in within single packages will make it easier to look for "source of truth" and is more maintainable rather than having values scattered all over the codebase
refs https://github.com/TryGhost/Team/issues/3051
- The filter was not working properly when there was no logged in member, but the announcement filter was set to "paid_members" only