Consolidate statistics aggregation

[alamb]

Is your feature request related to a problem or challenge?

There are at least three places in DataFusion where multiple Statistics objects are aggregated together, and they do so inconsistently:

1. get_statistics_with_limit: https://github.com/apache/arrow-datafusion/blob/e54894c39202815b14d9e7eae58f64d3a269c165/datafusion/core/src/datasource/statistics.rs#L34-L33
   2 . Parquet::infer_stats: https://github.com/apache/arrow-datafusion/blob/a892300a5a56c97b5b4ddc9aa4a421aaf412d0fe/datafusion/core/src/datasource/file_format/parquet.rs#L503-L581
2. Union::statistics: https://github.com/apache/arrow-datafusion/blob/c2e768052c43e4bab6705ee76befc19de383c2cb/datafusion/physical-plan/src/union.rs#L612-L611

(and we actually have another version of this in IOx)

Describe the solution you'd like

I would like to consolidate the three implementations into a StatisticsAggregator that knows how to aggregate multiple Statistics objects that is both documented and well tested.

Describe alternatives you've considered

No response

Additional context

No response

[alamb]

Update here is I have a PR in progress and expect it to be ready for review in the next day or two

[alamb]

#8254 has the basics in place, but I need to work on other higher priority items this week and next so this has been pushed lower in my priority list

[alamb]

@xudong963 do you think we have completed this issue now?

[xudong963]

@alamb nearly, I'll check the union stats tomorrow

[adriangb]

Bump on seeing if we should close this?