FEATURE: Add keywords support for site_settings search (#24146)

* FEATURE: Add keywords support for site_settings search

This change allows for a new `keywords` field that can be added to site
settings in order to help with searching. Keywords are not visible in
the UI, but site settings matching one of the contained keywords will
appear when searching for that keyword.

Keywords can be added for site settings inside of the
`config/locales/server.en.yml` file under the new `keywords` key.

```
site_settings
  example_1: "fancy description"
  example_2: "another description"

  keywords:
    example_1: "capybara"
```

* Add keywords entry for a recently changed site setting and add system specs

* Use page.visit now that we have our own visit

spec/system/page_objects/pages/admin_settings.rb

@@ -4,7 +4,12 @@ module PageObjects
   module Pages
     class AdminSettings < PageObjects::Pages::Base
       def visit_filtered_plugin_setting(filter)
-        visit("/admin/site_settings/category/plugins?filter=#{filter}")
+        page.visit("/admin/site_settings/category/plugins?filter=#{filter}")
+        self
+      end
+
+      def visit
+        page.visit("/admin/site_settings")
         self
       end
 
@@ -34,6 +39,15 @@ module PageObjects
           .map { |e| vals << e.text }
         vals
       end
+
+      def type_in_search(input)
+        find("input#setting-filter").send_keys(input)
+        self
+      end
+
+      def has_search_result?(setting)
+        page.has_selector?("div[data-setting='#{setting}']")
+      end
     end
   end
 end