Revert "settings: Remove auxiliary Content types where possible (#16744)" (#17768)

This breaks setting `{"scrollbar": {"show":"never"}}`
Release Notes:

- N/A

crates/extensions_ui/src/extensions_ui.rs

@@ -1000,7 +1000,7 @@ impl ExtensionsPage {
                             this.update_settings::<VimModeSetting>(
                                 selection,
                                 cx,
-                                |setting, value| *setting = VimModeSetting(value),
+                                |setting, value| *setting = Some(value),
                             );
                         }),
                     )),