Add `pg_lake` extensions to `flowdb`

[chrisjbrooks]

Is your feature request related to a problem? Please describe.
Interaction with parquet files is currently limited to read-only via use of parquet_fdw.

Describe the solution you'd like
Make pg_lake extensions available. This will enable interaction with Iceberg and data lake file.

Describe alternatives you've considered
None

Additional context
A pg_lake instance consists of two main components: PostgreSQL with the pg_lake extensions and pgduck_server. Parts of query execution are delegated to DuckDB through pgduck_server. We should evaluate pg_lake for production use, including understanding effective management of DuckDB processes.