Cannot run unit test on a remote elasticsearch instance

Since NXP-23142 we can choose which elasticsearch client is used to run unit test

# Embedded elasticsearch with rest client (default)
mvn -nsu test -Dnuxeo.test.elasticsearch.client=RestClient 
# Embedded elasticsearch with transport client
mvn -nsu test -Dnuxeo.test.elasticsearch.client=TransportClient

But specifying a remote elasticsearch cluster fails, tests are run against the embedded version:

mvn -nsu test -Dnuxeo.test.elasticsearch.addressList=http://localhost:9400

Even once the ESTestClientFactory fixed some tests will fail when using a remote Elasticsearch because of index cleaning when using aliases. (Embedded server is flushed between tests so it works).

We should fix this regression so tests can be run against a target Elasticsearch cluster in order to validate Elasticsearch version compatibility.