This is a preparatory commit for using isort for sorting all of our
imports, merging changes to files where we can easily review the
changes as something we're happy with.
These are also files with relatively little active development, which
means we don't expect much merge conflict risk from these changes.
This field is primarily intended to support avoiding displaying the
"more topics" feature in new organizations and streams, where we might
know that all messages in the stream are already available in the
browser.
Based on original work by Roman Godov, and significantly modified by
tabbott.
The second migration involved here could be expensive on Zulip Cloud,
but is unlikely to be an issue on other servers.
Tim Abbott
Challa Venkata Raghava Reddy