This commit makes it so the site settings filter controls and
the list of settings input editors themselves can be used elsewhere
in the admin UI outside of /admin/site_settings
This allows us to provide more targeted groups of settings in different
UI areas where it makes sense to provide them, such as on plugin pages.
You could open a single page for a plugin where you can see information
about that plugin, change settings, and configure it with custom UIs
in the one place.
In future we will do this in "config areas" for other parts of the
admin UI.
Followup to e37fb3042d
Some plugins like discourse-ai and discourse-saml do not
nicely change from kebab-case to Title Case (e.g. Ai, Saml),
and anyway this method of getting the plugin name is not
translated either.
Better to use the plugin setting category if it exists,
since that is written by a human and is translated.
1. Use `this.` instead of `{{action}}` where applicable
2. Use `{{fn}}` instead of `@actionParam` where applicable
3. Use non-`@` versions of class/type/tabindex/aria-controls/aria-expanded
4. Remove `btn` class (it's added automatically to all DButtons)
5. Remove `type="button"` (it's the default)
6. Use `concat-class` helper
In some languages, labels on the site settings navigation menu
get truncated. This adds titles to menu items, so users can see
untruncated labels on hover.
