Add a setting to let users only show unread channels in the sidebar. It defaults to showing "All Channels".
If "All Channels" is selected, the sidebar appears like normal.
If "Only unreads and direct messages" is selected, public, private and favorite channels without unreads are hidden from the sidebar. The favorites section title only shows up if a favorite channel receives an Unread message:
If "Only unreads and favorite channels" is selected, public, private, and direct message channels without unreads are hidden from the sidebar. The section titles are still visible:
When the setting is collapsed, the text should say one of the following:
"In my sidebar, show all channels."
"In my sidebar, show only unread channels and direct messages."
"In my sidebar, show only unread channels and favorite channels."