Description

There is absolutely no support for cartesian data in aggregations. There is a meta-task for adding Cartesian support for aggregations, and this issue is the first aggregation to add, the centroid aggregation.

It is modelled on the existing geo_centroid and as such could be called either:

• cartesian_centroid
• or just centroid

Sub-tasks:

• Refactor GeoPoint and GeoShape with generics #89388
• Centroid aggregation for cartesian points and shapes #89216
• Documentation