Bug 28268: Improve memory usage when indexing authorities in Elasticsearch

Bug 28268: Improve memory usage when indexing authorities in Elasticsearch

Retrieves the complete records one by one to avoid huge memory usage.

Note that this removes the call to GuessAuthTypeCode, but it is done later in Koha::SearchEngine::Elasticsearch::marc_records_to_documents (and was never done if you asked to index a single record with --authid parameter).

Test plan:
1. Apply patch
2. Reindex authorities: perl misc/search_tools/rebuild_elasticsearch.pl -a -d -v
3. Check that indexing completed successfully and results are correct.

Signed-off-by: Aleisha Amohia <aleishaamohia@hotmail.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>