Here we have migrated checkboxes of all general notifications to the table.
By general notifications we mean, Mobile, Email, Desktop audio, and visual
notifications.
This is a part of a bigger migration to simply our notifications setting
changing infrastructure for all streams and individual streams. Later we
will add more row to this for different categories of notifications in
addition to the current ones ("Streams" and "PMs, mentions, alerts").
Fixes: #12182.
Just updating this to no longer be incorrect; I expect we'll update this and
the rest of the Notifications section once we're done with the larger
notifications refactoring project.