A preview call can be quite expensive and cause timeout in a cluster. As a short term fix we identified 2 (hopefully) small fixes:

- make the call cancellable, the main issue here seems to be that preview calls search without using a parent task id(see this fix for data feeds: https://github.com/elastic/elasticsearch/pull/88142/files#diff-aba58244cb8f9dfa3ac3b6efeb02259e3d5956576f56c1ff5e243dd2aac27381)
- pass the timeout parameter of the preview call to the search call, currently a timeout can be specified, but is ignored for the inner search call, which is executed with no timeout (see https://www.elastic.co/guide/en/elasticsearch/reference/master/search-search.html#search-search-api-query-params).

Both changes are bugs and shall be relatively simple to implement and considered for backport to the 7.17 branch.

@przemekwitek can you have a look at this?

related: #88010
x-pack/plugin/transform/src/test/java/org/elasticsearch/xpack/transform/transforms/pivot/PivotTests.java
if (agg.equals(AggregationType.WEIGHTED_AVG.getName())) {
            return parseAggregations("""
                {
                "pivot_weighted_avg": {
                  "weighted_avg": {
                   "value": {"field": "values"},
                   "weight": {"field": "weights"}
                  }
                }
                }""");
        }
        if (agg.equals(AggregationType.FILTER.getName())) {
            return parseAggregations("""
                {
                  "pivot_filter": {
                    "filter": {
                      "term": {
                        "field": "value"
                      }
                    }
                  }
                }""");
        }
        if (agg.equals(AggregationType.GEO_LINE.getName())) {
            return parseAggregations("""
                {
                  "pivot_geo_line": {
                    "geo_line": {
                      "point": {
                        "field": "values"