Nested type modifiers/complex type

Example Trino SQL:
```sql
SELECT
row_id,
array_agg(
CAST(
ROW(
total_amount
)
AS
ROW(
total_amount Decimal(14,2)
)
)
ORDER BY payment_requested_date DESC
) AS payment_request_details
FROM
iceberg.my_table_name
GROUP BY 1
```

This throws an error when using `GenericDialect`, specifically when it tries to parse `Decimal(14,2)`: ```ParserError("Expected: type modifiers, found: ( at Line: 10, Column: 37")```

Stepping through the code it looks like this is because it does not support deeply nested definitions because `parse_optional_type_modifiers` does not allow `Token::LParen`.

This may be by design, but it may break parsing when you get to really complex queries (e.g. deeply nested rows).

从 GenericDialect 对嵌套类型定义和 parse_optional_type_modifiers 的处理开始，然后重现提供的查询以确认 Decimal(14,2) 失败。跟踪嵌套 ROW 类型的解析方式，并添加回归覆盖，表明该查询可以使用其嵌套类型修饰符成功解析。

由索引模型根据 Issue 内容生成。