This commit updates the existing 'Topics' settings UI
to add support for followed topics.
Changes:
- Add "Followed" as the first option in the topic status dropdowns.
- Modify the intro text.
- Replace the "Learn more." link with a question mark linking to
'/help/mute-a-topic' on the "Topic settings" heading.
The changes are visible in the development environment only.
Fixes#25918.
This commit adds filter_text_input class to various search inputs
used across the app. This new class is used to re-add the bootstrap
CSS rules such that we can remove the CSS from bootstrap.css.
This commit renames 'muted_topics_settings.hbs' to
'user_topics_settings.hbs', because the file now represents the
settings for topics with any visibility_policy, not just MUTED.