ERP5Workflow: add listbox for trigger_type in order to display nicely

how transition is triggered instead of '1' and '2'

bt5/erp5_workflow/SkinTemplateItem/portal_skins/erp5_workflow/Workflow_viewTransitionList/listbox_trigger_type.xml

+<?xml version="1.0"?>
+<ZopeData>
+  <record id="1" aka="AAAAAAAAAAE=">
+    <pickle>
+      <global name="ProxyField" module="Products.ERP5Form.ProxyField"/>
+    </pickle>
+    <pickle>
+      <dictionary>
+        <item>
+            <key> <string>delegated_list</string> </key>
+            <value>
+              <list>
+                <string>items</string>
+                <string>title</string>
+              </list>
+            </value>
+        </item>
+        <item>
+            <key> <string>id</string> </key>
+            <value> <string>listbox_trigger_type</string> </value>
+        </item>
+        <item>
+            <key> <string>message_values</string> </key>
+            <value>
+              <dictionary>
+                <item>
+                    <key> <string>external_validator_failed</string> </key>
+                    <value> <string>The input failed the external validator.</string> </value>
+                </item>
+              </dictionary>
+            </value>
+        </item>
+        <item>
+            <key> <string>overrides</string> </key>
+            <value>
+              <dictionary>
+                <item>
+                    <key> <string>field_id</string> </key>
+                    <value> <string></string> </value>
+                </item>
+                <item>
+                    <key> <string>form_id</string> </key>
+                    <value> <string></string> </value>
+                </item>
+                <item>
+                    <key> <string>target</string> </key>
+                    <value> <string></string> </value>
+                </item>
+              </dictionary>
+            </value>
+        </item>
+        <item>
+            <key> <string>tales</string> </key>
+            <value>
+              <dictionary>
+                <item>
+                    <key> <string>field_id</string> </key>
+                    <value> <string></string> </value>
+                </item>
+                <item>
+                    <key> <string>form_id</string> </key>
+                    <value> <string></string> </value>
+                </item>
+                <item>
+                    <key> <string>items</string> </key>
+                    <value>
+                      <persistent> <string encoding="base64">AAAAAAAAAAI=</string> </persistent>
+                    </value>
+                </item>
+                <item>
+                    <key> <string>target</string> </key>
+                    <value> <string></string> </value>
+                </item>
+                <item>
+                    <key> <string>title</string> </key>
+                    <value> <string></string> </value>
+                </item>
+              </dictionary>
+            </value>
+        </item>
+        <item>
+            <key> <string>values</string> </key>
+            <value>
+              <dictionary>
+                <item>
+                    <key> <string>field_id</string> </key>
+                    <value> <string>my_list_field</string> </value>
+                </item>
+                <item>
+                    <key> <string>form_id</string> </key>
+                    <value> <string>Base_viewFieldLibrary</string> </value>
+                </item>
+                <item>
+                    <key> <string>items</string> </key>
+                    <value>
+                      <list>
+                        <tuple>
+                          <string>Automatic</string>
+                          <string>0</string>
+                        </tuple>
+                        <tuple>
+                          <string>User_Action</string>
+                          <string>1</string>
+                        </tuple>
+                        <tuple>
+                          <string>Workflow_Method</string>
+                          <string>2</string>
+                        </tuple>
+                      </list>
+                    </value>
+                </item>
+                <item>
+                    <key> <string>target</string> </key>
+                    <value> <string>Click to edit the target</string> </value>
+                </item>
+                <item>
+                    <key> <string>title</string> </key>
+                    <value> <string>Trigger Type</string> </value>
+                </item>
+              </dictionary>
+            </value>
+        </item>
+      </dictionary>
+    </pickle>
+  </record>
+  <record id="2" aka="AAAAAAAAAAI=">
+    <pickle>
+      <global name="TALESMethod" module="Products.Formulator.TALESField"/>
+    </pickle>
+    <pickle>
+      <dictionary>
+        <item>
+            <key> <string>_text</string> </key>
+            <value> <string>python: [(\'Automatic\', 0), (\'User_Action\', 1), (\'Workflow_Method\', 2)]</string> </value>
+        </item>
+      </dictionary>
+    </pickle>
+  </record>
+</ZopeData>