Typed Series for json_path_match

[cjermain]

Nested JSON fields are unfortunately common in some parquet and JSON files. While polars provides a json_path_match function, it can only return a string in the current implementation. This makes it of limited value when working with nested JSON fields of various types within a Utf8Chunked array. I did a POC locally showing that correct typing can be achieved with a few tweaks to json_path_match, and a modification of the deserialization approach in arrow2. I put up a PR on arrow2 (jorgecarleitao/arrow2#989) to address the underlying support for JSON parsing from a arrow2::array::Utf8Array, and will follow up with a PR that uses that support to output a Series with proper type.

When this is added, I think the API for json_path_match should change as follows:

fn json_path_match(&self, json_path: &str) -> Result<Series> {
    ...
}

[ritchie46]

That sounds like a good idea to me!