Add trend management to admin API (#24257)

app/serializers/rest/admin/trends/links/preview_card_provider_serializer.rb

@@ -0,0 +1,10 @@
+# frozen_string_literal: true
+
+class REST::Admin::Trends::Links::PreviewCardProviderSerializer < ActiveModel::Serializer
+  attributes :id, :domain, :trendable, :reviewed_at,
+             :requested_review_at, :requires_review
+
+  def requires_review
+    object.requires_review?
+  end
+end