Add hard_bounds for histograms

[stevejgordon]

Please consider this a WIP for review to check I'm on the best track.

Adds hard_bounds parameter to histogram aggregations per elastic/elasticsearch#59175.

Questions:

For now, I've made HardBounds a copy of ExtendedBounds. I suspect we can't safely rename this public type to something more general. An option would be to define the properties in a base class from which these two could derive. Perhaps overkill here though.

I've updated two usage tests to confirm that the final JSON is built as expected. Are there any further tests we should be considering on additional such as this one?

[Mpdreamz]

Those tests are the correct place to add them but they are breaking the integration assertions:

https://github.com/elastic/elasticsearch-net/pull/5098/files#diff-abdcda181162c237e14568b13e1eda0e3aae3cc12efcc1f9b0c33e86bf203ccfR127

[xUnit.net 00:01:51.9685150]     Tests.Aggregations.Bucket.DateHistogram.DateHistogramAggregationUsageTests.ReturnsExpectedResponse [FAIL]
  X Tests.Aggregations.Bucket.DateHistogram.DateHistogramAggregationUsageTests.ReturnsExpectedResponse [939ms]
  Error Message:
   Tests.Framework.EndpointTests.ResponseAssertionException : Expected value to be greater than 10, but found 0.
Response Under Test:
Valid NEST response built from a successful (200) low level call on POST: /projects-only/_search?pretty=true&error_trace=true&typed_keys=false
# Audit trail of this API call:
 - [1] HealthyResponse: Node: http://localhost:9200/ Took: 00:00:00.0964947
# Request:
{"aggs":{"projects_started_per_month":{"aggs":{"project_tags":{"aggs":{"tags":{"terms":{"field":"tags.name"}}},"nested":{"path":"tags"}}},"date_histogram":{"extended_bounds":{"max":"2016-06-06T12:01:02.123","min":"2014-06-06T12:01:02.123"},"hard_bounds":{"max":"2016-06-06T12:01:02.123","min":"2014-06-06T12:01:02.123"},"field":"startedOn","format":"yyyy-MM-dd'T'HH:mm:ss||date_optional_time","calendar_interval":"month","min_doc_count":2,"missing":"2015-06-06T12:01:02.1230000","order":{"_count":"asc"}}}},"query":{"term":{"type":{"value":"project"}}},"size":0}
# Response:
{
  "took" : 7,
  "timed_out" : false,
  "_shards" : {
    "total" : 2,
    "successful" : 2,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 100,
      "relation" : "eq"
    },
    "max_score" : null,
    "hits" : [ ]
  },
  "aggregations" : {
    "projects_started_per_month" : {
      "buckets" : [ ]
    }
  }
}

This might warrant their own *UsageTests.

You can run just a particular test with:

.\built.bat integrate latest readonly DateHistogramAggregation

[stevejgordon]

@Mpdreamz I've reworked the tests, adding specific ones as you suggested. These seem to pass locally now too using .\build.bat integrate 7.10.0 readonly and .\build.bat test.

[stevejgordon]

@Mpdreamz / @russcam - On further review I noticed that this was already handled for extended_bounds by adding date_optional_time to the format string. I've updated the code so we apply the same here and now formatting works as expected.

One thing I did notice is that the callout from https://github.com/elastic/elasticsearch-net/blob/master/tests/Tests/Aggregations/Bucket/DateHistogram/DateHistogramAggregationUsageTests.cs#L42 is not rendered into the final documentation - https://github.com/elastic/elasticsearch-net/blob/master/docs/aggregations/bucket/date-histogram/date-histogram-aggregation-usage.asciidoc

Is there something extra needed to make that work? It's affecting the current 7.x documentation. https://www.elastic.co/guide/en/elasticsearch/client/net-api/current/date-histogram-aggregation-usage.html

[Mpdreamz]

++ this hack comes back to me now 😄