Add supplier_reference field to form

InvenTree/order/templates/order/order_base.html

@@ -170,6 +170,7 @@ $("#edit-order").click(function() {
             supplier: {
             },
             {% endif %}
+            supplier_reference: {},
             description: {},
             target_date: {
                 icon: 'fa-calendar-alt',

InvenTree/templates/js/order.js

@@ -44,6 +44,7 @@ function createPurchaseOrder(options={}) {
             supplier: {
                 value: options.supplier,
             },
+            supplier_reference: {},
             description: {},
             target_date: {
                 icon: 'fa-calendar-alt',