FIX: Sort plugins by their setting category name (#25128)

Some plugins have names (e.g. discourse-x-yz) that
are totally different from what they are actually called,
and that causes issues when showing them in a sorted way
in the admin plugin list.

Now, we should use the setting category name from client.en.yml
if it exists, otherwise fall back to the name, for sorting.
This is what we do on the client to determine what text to
show for the plugin name as well.

lib/plugin/instance.rb

@@ -122,7 +122,11 @@ class Plugin::Instance
     @enabled_site_setting ? SiteSetting.get(@enabled_site_setting) : true
   end
 
-  delegate :name, :name_without_prefix, to: :metadata
+  delegate :name, to: :metadata
+
+  def humanized_name
+    (setting_category_name || name).delete_prefix("Discourse ").delete_prefix("discourse-")
+  end
 
   def add_to_serializer(
     serializer,
@@ -1369,6 +1373,16 @@ class Plugin::Instance
 
   private
 
+  def setting_category
+    return if @enabled_site_setting.blank?
+    SiteSetting.categories[enabled_site_setting]
+  end
+
+  def setting_category_name
+    return if setting_category.blank? || setting_category == "plugins"
+    I18n.t("admin_js.admin.site_settings.categories.#{setting_category}")
+  end
+
   def validate_directory_column_name(column_name)
     match = /\A[_a-z]+\z/.match(column_name)
     unless match