Bug 17372: Standardize Elasticsearch paths

Bug 17372: Standardize Elasticsearch paths

What we currently have:
Koha/ElasticSearch.pm
Koha/ElasticSearch/Indexer.pm
Koha/SearchEngine/Elasticsearch/QueryBuilder.pm
Koha/SearchEngine/Elasticsearch/Search.pm

What we want:
Koha/SearchEngine/Elasticsearch.pm
Koha/SearchEngine/Elasticsearch/Indexer.pm
Koha/SearchEngine/Elasticsearch/QueryBuilder.pm
Koha/SearchEngine/Elasticsearch/Search.pm

Test plan:
  % git grep -i Koha::ElasticSearch
  % git grep ElasticSearch|grep -v Catmandu::Store::ElasticSearch
should not return any result

Do a full reindex and search for records

Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Brendan Gallagher <brendan@bywatersolutions.com>
(cherry picked from commit df3df9cf7199c464565742af59bd48006d93cfdf)
Signed-off-by: Frédéric Demians <f.demians@tamil.fr>