extend data bucket stream to index by both, ingestion-order and by key

This is needed for synchronisation with a file system. Then we need to address
each bucket by key (e.g. filename). But we also need to address by the order of
ingestion for processing with progress indicator.

bt5/erp5_wendelin/DocumentTemplateItem/portal_components/document.erp5.DataBucketStream.xml

@@ -46,8 +46,8 @@
             <key> <string>text_content_warning_message</string> </key>
             <value>
               <tuple>
-                <string>W: 54, 21: Redefining built-in \'id\' (redefined-builtin)</string>
-                <string>W: 67, 18: Redefining built-in \'id\' (redefined-builtin)</string>
+                <string>W:124, 21: Redefining built-in \'id\' (redefined-builtin)</string>
+                <string>W:180, 19: Redefining built-in \'id\' (redefined-builtin)</string>
               </tuple>
             </value>
         </item>