Revert data lake download script parameter rename as it breaks ebulk client download

See merge request nexedi/wendelin!157

bt5/erp5_wendelin_data_lake_ingestion/SkinTemplateItem/portal_skins/erp5_wendelin_data_lake/ERP5Site_getDataStreamChunk.py

 try:
   start_offset = int(float(start_offset))
   end_offset = int(float(end_offset))
-  data_stream = context.restrictedTraverse(identity)
+  data_stream = context.restrictedTraverse(id)
   data_stream_chunk = ''.join(data_stream.readChunkList(start_offset, end_offset))
   return data_stream_chunk
 except Exception as e:
-  context.logEntry("Exception getting Data Stream (id '%s') content: %s." % (identity, str(e)))
+  context.logEntry("Exception getting Data Stream (id '%s') content: %s." % (id, str(e)))
   raise e

bt5/erp5_wendelin_data_lake_ingestion/SkinTemplateItem/portal_skins/erp5_wendelin_data_lake/ERP5Site_getDataStreamChunk.xml

@@ -50,7 +50,7 @@
         </item>
         <item>
             <key> <string>_params</string> </key>
-            <value> <string>identity, start_offset, end_offset</string> </value>
+            <value> <string>id, start_offset, end_offset</string> </value>
         </item>
         <item>
             <key> <string>id</string> </key>