These aggregations are not experimental anymore but some of their parameters
still are:
- `precision_threshold` and `rehash` on `cardinality`
- `compression` on percentiles(-ranks)
Close#9560
Percentile Rank Aggregation is the reverse of the Percetiles aggregation. It determines the percentile rank (the proportion of values less than a given value) of the provided array of values.
Closes#6386
Our improvements to t-digest have been pushed upstream and t-digest also got
some additional nice improvements around memory usage and speedups of quantile
estimation. So it makes sense to use it as a dependency now.
This also allows to remove the test dependency on Apache Mahout.
Close#6142