Native JSON data type support

[JichaoS]

Hello!

BigQuery supports the JSON data type: https://cloud.google.com/bigquery/docs/reference/standard-sql/json-data

Are there any plans to support this datatype in querying?

[lquerel]

This is definitely something we need to add in this crate. However, I don't know yet when I will be able to add it, as my current schedule is already quite busy.

Note that this crate is open for contribution.