Some files already were using `noop` in place of `() => {}`.
It's both clearer what it means and is easier to type.
This updates all test files to fully use `noop`, and
adds a shared import from the test lib file.
Now, the topic wildcard mention follows the following
rules:
* If the topic has less than 15 participants , anyone
can use @ topic mentions.
* For more than 15, the org setting 'wildcard_mention_policy'
determines who can use @ topic mentions.
Earlier, topic wildcard mentions followed the same restriction
as stream wildcard mentions, which was incorrect.
Fixes part of #27700.
This should cause no functional changes.
This is part of a multi-step effort to move away
from using stream names to reference streams, now
that it's impossible for a user to write a message
with an invalid stream name (since switching to
the dropdown).
This lets us simplify the long-ish ‘../../static/js’ paths, and will
remove the need for the ‘zrequire’ wrapper.
Signed-off-by: Anders Kaseorg <anders@zulip.com>