Websearch: fix record numbering for pagination

* Adds the nb_found argument to print_records allowing for a different
  list of records to be printed and number of records found, when we are
  only printing a subset of a total number of records found.

(closes #1762)

Signed-off-by: Nikolaos Kasioumis <nikolaos.kasioumis@cern.ch>
Merge pull request #42 from kasioumis/master-search-engine-nb_found-fix

Websearch: fix record numbering for pagination