* Expose agg usage in Feature Usage API
Counts usage of the aggs and exposes them on the _nodes/usage/.
Closes#53746
* Refactor to include non value sources aggregations
* Fix reported values source type for parent and children aggs
* Refactor SearchModule constructor
* Fix subtype in TTest and IPRanges
* Fix more subtypes in aggs that don't register themselves
* Fix doc tests
* Fix docs
* Fix ScriptedMetricAggregatorTests
* Fix compilation issues after merge
* Fix merge fallout
* This gets stale quickly...
* Address review comments
* Fix tests that were missing proper agg registration in the search module
* Fix ScriptedMetricAggregatorTests
* Address review comments
Co-authored-by: Elastic Machine <elasticmachine@users.noreply.github.com>
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