All the elements to which `display-none` class
is applied, are handled with `.show()`/`.hide()`
functions instead of `.addClass('display-none')`
and `.removeClass('display-none')`.
Therefore, we should use apply `display: none;`
to elements with `style` attribute.
This commits removes all usage of `display-none`.
This adds the same "x" button as we have in "stream search" or "people
search" to the user status modal.
The button is shown if someone types something, or if the status
message was already set (meaning there was already a value in the
input field). If the input field is empty, the button is not visible.
This fixes the follow-up comments from #12179.
This commit transitions all styles in app.css in the Django pipeline
to being compiled by webpack in an app-styles bundle, and renames the
various files to now be processed as SCSS.
To implement this transition, we move the old CSS file refernces in
settings.py and replace them with a bundle declared in
`webpack.assets.json` and includedn in the index.html template
Tweaked by tabbott to keep the list of files in `app.css` in
`webpack.assets.json`, and to preserve the ordering from the old
`settings.py`.