Add secondary dialog for creating new supplier

InvenTree/order/templates/order/purchase_orders.html

@@ -158,6 +158,14 @@ $("#po-create").click(function() {
     launchModalForm("{% url 'po-create' %}",
         {
             follow: true,
+            secondary: [
+                {
+                    field: 'supplier',
+                    label: '{% trans "New Supplier" %}',
+                    title: '{% trans "Create new Supplier" %}',
+                    url: '{% url "supplier-create" %}',
+                }
+            ]
         }
     );
 });