Hi I have a general question on Iceberg's data type system. Iceberg has a well defined type spec <https://iceberg.apache.org/spec/#schemas-and-data-types> which can be mapped to types in Avro, Parquet, ORC. If users want to use Iceberg and extend the universe of data types (e.g., adding custom types on top of existing types), is it possible to do this w/o changing Iceberg core modules?
Chen
