erp5_item: Change default sorting of Item_viewTrackingList/listbox

to descending date and move the sorting to Listbox definition
instead of list method

bt5/erp5_item/SkinTemplateItem/portal_skins/erp5_item/Item_getTrackingList.py

@@ -5,9 +5,6 @@ if current:
 else:
   method = portal.portal_simulation.getTrackingList
 
-# tracking list is much more readable if locations are sorted by dates.
-kw.setdefault('sort_on', (('date', 'ascending',),))
-
 history_list = []
 for brain in method(aggregate_uid=context.getUid(), **kw):
   explanation = brain.getExplanationValue()

bt5/erp5_item/SkinTemplateItem/portal_skins/erp5_item/Item_viewTrackingList/listbox.xml

@@ -12,6 +12,7 @@
               <list>
                 <string>columns</string>
                 <string>list_method</string>
+                <string>sort</string>
                 <string>sort_columns</string>
                 <string>title</string>
               </list>
@@ -135,6 +136,17 @@
                       <persistent> <string encoding="base64">AAAAAAAAAAI=</string> </persistent>
                     </value>
                 </item>
+                <item>
+                    <key> <string>sort</string> </key>
+                    <value>
+                      <list>
+                        <tuple>
+                          <string>date</string>
+                          <string>DESC</string>
+                        </tuple>
+                      </list>
+                    </value>
+                </item>
                 <item>
                     <key> <string>sort_columns</string> </key>
                     <value>