Bug 28610: Elasticsearch 7 - hits.total is now an object

Bug 28610: Elasticsearch 7 - hits.total is now an object

In Elasticsearch 7 hits.total is now an object which is not always an exact
value. You can always get an exact total by adding a track_total_hits
parameter set to true when using the Elasticsearch search method

To test:
1) Run prove t/db_dependent/Koha/SearchEngine/Elasticsearch/Search.t
2) If you observe an error about types, apply patch for bug 25669
3) Run prove t/db_dependent/Koha/SearchEngine/Elasticsearch/Search.t
4) Observe that tests with count fail
5) Apply patch
6) Observe that tests with count pass
7) Sign off

Sponsored-by: Lund University Library
Signed-off-by: Julian Maurice <julian.maurice@biblibre.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>