Pipe dream: Add SQL support for pipe operator defined by GoogleSQL

GoogleSQL (formerly ZetaSQL) adds the pipe operator |> to the SQL language.

The pipe operator is described here: https://research.google/pubs/pub1005959/

The paper does a good job of describing why it's a useful feature.

MariaDB would be an even cooler/better product if it added support for the |> operator in SQL queries. Practically speaking, this would be a backward compatible feature, and (I'm guessing) probably not too difficult to implement within MariaDB's existing architecture.