FEATURE: public custom sidebar sections visible to anonymous (#20931)

Previously, public custom sections were only visible to logged-in users. In this PR, we are making them visible to anonymous as well.

The reason is that Community Section will be moved into custom section model to be easily editable by admins.

app/serializers/current_user_serializer.rb

@@ -79,8 +79,9 @@ class CurrentUserSerializer < BasicUserSerializer
 
   def sidebar_sections
     SidebarSection
+      .public_sections
+      .or(SidebarSection.where(user_id: object.id))
       .includes(sidebar_section_links: :linkable)
-      .where("public OR user_id = ?", object.id)
       .order("(public IS TRUE) DESC")
       .map { |section| SidebarSectionSerializer.new(section, root: false) }
   end