Settings editor: Support .enabled to hide other settings in the namespace by convention

Related/parent issue: #70589 @eamodio suggested the idea of special settings that would hide other settings, that got me thinking we have this pattern already but don't hide them. In the screenshot below, only the top setting means anything unless it's checked, so we could hide them to reduce the overwhelming number of settings available:  This is similar to how most GUIs would disable settings when the feature is disabled. I'm not sure whether they should show up when searching, maybe they should but be faded/disabled out or something and point to the parent `.enabled` setting?