Bug 30882: Add max_result_window to index config

Elasticsearch number of results is by default limited by setting "index.max-result-window", default value is 10000.
https://www.elastic.co/guide/en/elasticsearch/reference/current/index-modules.html#index-max-result-window

We use this setting:
44d6528b56/Koha/SearchEngine/Elasticsearch/Search.pm (L411)

I propose we add this setting in index config.

Test plan:
1) Use Elasticsearch
2) Apply patch and flush memcached
3) Rebuild indexes: misc/search_tools/rebuild_elasticsearch.pl -v -b -d
4) Check the settings of index (when using koha-testing-docker*):
   curl 'es:9200/koha_kohadev_biblios/_settings?pretty&filter_path=**.max_result_window'
5) You should see:
   "max_result_window" : "1000000"

* You also need to add this setting to the es section in koha-testing-docker's
docker-compose.yml (after the networks configuration):
     ports:
         - "9200:9300"

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Victor Grousset/tuxayo <victor@tuxayo.net>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>

admin/searchengine/elasticsearch/index_config.yaml

@@ -42,5 +42,6 @@ index:
         pattern: '\s*(?<!\p{Lu})[.\-,;]*\s*$'
         replacement: ''
 index.mapping.total_fields.limit: 10000
+index.max_result_window: 1000000
 index.number_of_replicas: 1
 index.number_of_shards: 5