New catalog can't drop functions with table arguments

```sql
CREATE FUNCTION f(x INT) RETURNS TABLE (y INT) AS 'SELECT 1' LANGUAGE sql;
DROP FUNCTION f(INT);
```

On the experimental parser this returns `relation "f" does not exist`.

This is because `f()` has a table argument `y INT` that is tripping up `DROP FUNCTION`. The catalog needs to be updated to detect table parameters and not use them when finding a function signature.