[Elasticsearch / Opensearch] Recheck the usage of doc_values for filtering

[alexander-schranz]

Currently we are using doc_values to true for filtering none indexed fields. This is documented as not being as performant as query indexed fields: https://www.elastic.co/guide/en/elasticsearch/reference/current/doc-values.html. Which we maybe need to recheck.

Interesting is that Opensearch and Elasticseach has different default values which did make tests fail in Opensearch for #64 (commit) and required to set doc_values to true there:

Opensearch: doc_values: false doc here
Elasticsearch: doc_values: true doc here

Update the doc_values: true set on opensearch did not work like expected: opensearch-project/OpenSearch#5770

Currently in opensearch we workaround making all filterable fields also index. This should be rechecked if this should also be the behaviour for elasticsearch. This maybe requires us to switch from query_string search to match search where we put only searchable fields into it.