Is your feature request related to a problem or challenge? Please describe what you are trying to do.

per @nrc:

We want to support extracting parts of intervals (like days, etc) in DataFusion. It's also desirable functionality in Arrow for it's own sake, although I don't have a directly motivating use case.

Related to apache/datafusion#6327

Describe the solution you'd like

Implement date_part for Interval

Describe alternatives you've considered

Additional context