adding statrs statistical functions

### Is your feature request related to a problem or challenge?

Hi Datafusion,

Great software - thanks!

For some of my bioinformatics applications I needed to call some statistical functions, and after creating a couple of ScalarUDFs for my immediate problem, I thought it would be pretty nice to have them available as a library, since they are generally useful for people doing data science or bioinformatics.

### Describe the solution you'd like

I've made a start on packaging up the statistical functions as a library - see https://github.com/drtconway/datafusion-statrs

Feedback on what is required to bring this to a level for inclusion in contrib would be welcome.

### Describe alternatives you've considered

Adding ScalarUDFs in an ad hoc way to applications is perfectly feasible, but it would be preferable to do a thorough job of it once.

### Additional context

_No response_

Start by reviewing the linked datafusion-statrs repository and the DataFusion contribution conventions for libraries in contrib. Determine the requirements and acceptance criteria for bringing the statistical functions to an inclusion-ready state, then confirm that the proposed scope and integration path are agreed upon.

Written by the indexing model from the issue text.