DDL -> avro

Support ddl as string (e.g. from pg_dump) to avro. e.g. 

```
a = """
CREATE TABLE public.abc (
    a integer NOT NULL,
    b integer NOT NULL,
    created_at timestamp with time zone,
    c integer,
    hello text[],
    updated_at timestamp without time zone
);
"""  # or get from somewher
avro_schema = get_avro_from_ddl(a)
```