Introduce a new class "table-sticky-headers" in the settings
and organisation settings HTML table tags and it is used
to make the table headers fix at the top. This commit also
add the background-color and hover properties to the
settings and organisation settings table to make them look
similar to the recent_topics_table.
This commit fixes a small bug in the
settings/muted-topics pane.
When there are zero muted topics, the
"You have not muted any topics yet." message
was not shown.
This is fixed by adding the `required-text`
class to the table body.
The bug was introduced in 3bc818b9f7.
The set_up_muted_topics_ui and templates have been
refactored to use list_render.
This is done to support filtering and sorting of
the muted stream topics.
This also includes the addition of a new Date muted header.