mrp: allow to cancel auto_planned orders

Avoid the need to go through planned state before cancelling

bt5/erp5_mrp/WorkflowTemplateItem/portal_workflow/production_order_workflow/states/auto_planned.xml

@@ -28,6 +28,8 @@
             <key> <string>transitions</string> </key>
             <value>
               <tuple>
+                <string>cancel</string>
+                <string>cancel_action</string>
                 <string>order</string>
                 <string>order_action</string>
                 <string>plan</string>