[Rust] [DataFusion] Improve ergonomics of registering UDFs

[asfimport]

Creating and registering UDFs currently requires quite a lot of boilerplate code and it would be good to improve this. See the comments on #6749 for more details.

Reporter: Andy Grove / @andygrove

Related issues:

• [Rust] [DataFusion] Improve API for usage of UDFs (is duplicated by)

_{Note: This issue was originally created as ARROW-8253. Please see the migration documentation for further details.}

[asfimport]

Andy Grove / @andygrove:
@jorgecarleitao I think this one can be closed now?

[asfimport]

Jorge Leitão / @jorgecarleitao:
I agree that we fixed this during ARROW-9836. I marked it as resolved and duplicated by that one. I hope it is fine.