[DS-1352] - Itemimport replace issue

This change fixes the JIRA Ticket: https://jira.duraspace.org/browse/DS-1352

When doing a batch import with option replace instead of deleting the item and creating a new one, it replaces all the metadatam and bitstreams for the item. This solves statistic issues that use the item_id has reference.

ex:
 -> check item_id for item
./dspace import --replace -c  <col_handle> -s <src_dir> -m mapfile -e <user>
 -> check again item_id for item