[Rollup] Support range aggregations

[polyfractal]

I think we can support some range aggregations on the existing data that we collect. E.g. if the ranges specify are compatible with the bucketing intervals collected by the date_histogram/histogram, ranges will work as expected.

We could also implement new groupings specifically for the range aggregation. It's a little less convenient, less efficient, and still has issues with bucket compatibility (there's no guarantee the ranges in the config match the ranges in the query).

[elasticmachine]

Pinging @elastic/es-search-aggs

[colings86]

I think supporting ranges at query time is a good idea. I think we should separate out the index time question into a different issue as that requires more work and I'm personally not sure we could implement it in a way thats easy to explain to the user

[polyfractal]

Agreed. Once we get #32052 merged, I think implementing query-time ranges should be reasonably straightforward. That PR does most of the heavy lifting wrt validating time intervals, so we can just piggyback on that and validate the ranges too.

[csoulios]

The team discussed this issue and it looks this idea is far from the current approach for rollups/downsampling.