Add examples for JSON and BSON logical types

[alamb]

Recently, @emkornfield asked apache/parquet-site#153 (comment)

Just wanted to check for JSON and BSON other engines do support this with the caveat that they just pass through. Does polars not support them at all?

This was in the context of if polars supported a particular operation on such files However, there were no such files I could find in the parquet-testing repo that I could check with.

Thus I would like some example parquet files with JSON and BSON logical types, as specified https://parquet.apache.org/docs/file-format/types/logicaltypes/

These should be small files and come with a small readme that explains how they were created and what they contain

This would also help others implementing parquet to test their implementations with such files

[emkornfield]

IIRC, I think Arrow C++ supports serializing canonical arrow JSON extension type to be marked with JSON (or at least there was an effort to do so that might have stalled).

[alamb]

I am pretty sure the Rust writer can also annotate a record batch with the correct logical types (if you write an Arrow array with the Json canonical type: https://docs.rs/arrow-schema/57.3.0/arrow_schema/extension/enum.CanonicalExtensionType.html#variant.Json

I had a half written example to do this but I ran out of time