Replaces usage of the word "bookmark" with "star"/"starred" in order to be more
consistent with the UI and database models, and to reduce confusion with
"bookmarklet" and integration features.
This is in preparation of future work on read-it-later features.
Which are also not called "bookmarks" to prevent any further confusion.
https://github.com/orgs/miniflux/discussions/3719
Related-to: https://github.com/miniflux/v2/pull/2219
Currently there's no way through the API to mimic the Unread page of the client.
This is now possible by filtering on globally_visible=true and status=unread.
rand.Intn(math.MaxInt64) causes tests to fail on 32-bit architectures.
Use the simpler rand.Int() instead, which still provides plenty of room
for generating pseudo-random test usernames.
