Position new record based on order

We sent an order to the client for action and xxx2Many so its screen has
always a default order set.
To position a new record on non editable tree, we use the order of the 'id'
column if presents.

issue8880
review276501003

view/production_lead_time_list_sequence.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0"?>
 <!-- This file is part of Tryton.  The COPYRIGHT file at the top level of
 this repository contains the full copyright notices and license terms. -->
-<tree sequence="sequence" editable="bottom">
+<tree sequence="sequence" editable="1">
     <field name="bom" widget="selection"/>
     <field name="lead_time"/>
 </tree>