WebComment: fix for get_first_comments_or_remarks
WebComment: fix for get_first_comments_or_remarks

* Updates and fixes template functions so that
  `get_first_comments_or_remarks` is not broken anymore.
  (closes #2522) (PR #2523)

Tested-by: Tibor Simko <c7116e45300b163846dc01f3ed02116e3f8ef7a5@cern.ch>

tiborsimko/invenio,inveniosoftware/invenio,inveniosoftware/invenio,tiborsimko/invenio