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.
For more clarity, the 3 related functions `is_search` in `filter.js`,
`message_list.js` and `message_list_data.js` are all renamed to
`is_keyword_search`.
This is logic from 10 years ago (dbc4798594)
that is no longer relevant. It seems like we used to show the
search bar open all the time and only showed the buttons when
there was focus in the search bar. Now we close the search bar
when it's not being used, and no longer need to update button
visibility or disable the search close button.
This in-progress feature was started in 2018 and hasn't
been worked on much since. It's already in a broken state,
which makes it hard to iterate on the existing search bar
since it's hard to know how those changes will affect search
pills.
We do still want to add search pills eventually, and when
we work on that, we can refer to this diff to readd the
changes back.
Evy Kassirer
N-Shar-ma
evykassirer
Karl Stolley
YashRE42
Lalit
evykassirer