Add improvements to response _DESERIALIZER
This PR adds a number of enhancements to several response classes.
co.elastic.clients.elasticsearch.security:
DisableUserResponseEnableUserResponseChangePasswordResponse
co.elastic.clients.elasticsearch.indices:
SimulateIndexTemplateResponse
For the response that returns an empty object, or has a possibility according to the server-side code, _DESERIALIZER should use emptyObject(T) from the JsonpDeserializer.
For more detailed specifications regarding this PR, please refer to https://github.com/elastic/elasticsearch-java/issues/718#issuecomment-2027988172.
Looks fine to me at a glance, but unfortunately not in a position to test ATM and don't have permissions to make a useful review.
Appreciate for the feedback! I hope to get further comments from this open source administrators.