This changes removes the SearchResponseListener that was used by the ExpandCollapseSearchResponseListener to expand collapsed hits.
The removal of SearchResponseListener is not a breaking change because it was never released.
This change also replace the blocking call in ExpandCollapseSearchResponseListener by a single asynchronous multi search request. The parallelism of the expand request can be set via CollapseBuilder#max_concurrent_group_searches
Closes#23048