🚧 Add OrderMetadataValues module for boot up

This module is needed for the application to boot up because it is being
called by OER and ETD.

app/models/concerns/order_metadata_values.rb

@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+module OrderMetadataValues
+  extend ActiveSupport::Concern
+
+  included do
+    def self.multi_valued_properties_for_ordering
+      properties.collect do |prop_name, node_config|
+        # Only concerned with properties displayed to end users
+        next if %w[head tail based_near].include?(prop_name)
+
+        prop_name.to_sym if node_config.instance_variable_get(:@opts)&.dig(:multiple)
+      end.compact
+    end
+
+    prepend OrderAlready.for(*multi_valued_properties_for_ordering)
+  end
+end