Code generation for PostgreSQL composite types

### Things to check first

- [X] I have searched the existing issues and didn't find my feature already requested there

### Feature description

Right now if a column has a composite type, it is generated as `Column(NullType)` with Python type `Any`. With [`CompositeType`](https://sqlalchemy-utils.readthedocs.io/en/latest/data_types.html#module-sqlalchemy_utils.types.pg_composite) from sqlalchemy-utils maybe it's possible to generate code for composite types.

### Use case

There would be somewhat nicer syntax for setting and getting columns with composite types, and more information from the schema would be represented in Python form.