Add moderation note (#5240)

* Add moderation note

* Add frozen_string_literal

* Make rspec pass

spec/helpers/admin/account_moderation_notes_helper_spec.rb

@@ -0,0 +1,15 @@
+require 'rails_helper'
+
+# Specs in this file have access to a helper object that includes
+# the Admin::AccountModerationNotesHelper. For example:
+#
+# describe Admin::AccountModerationNotesHelper do
+#   describe "string concat" do
+#     it "concats two strings with spaces" do
+#       expect(helper.concat_strings("this","that")).to eq("this that")
+#     end
+#   end
+# end
+RSpec.describe Admin::AccountModerationNotesHelper, type: :helper do
+  pending "add some examples to (or delete) #{__FILE__}"
+end