"parquet-tools cat -j" should not output metadata

Parquet-tools cat -help says:

```

parquet-tools cat:
Prints the content of a Parquet file. The output contains only the data, no
metadata is displayed
```

Let's say I have a structure like this in a Parquet file:
```json

{
"account":
[
{
"accountDepositType": "NA",
"accountNumber": "NA",
"accountHolderType": "NA"
}
]
}
```

it is extracted like this

```json

{
"account": {
"list": [
{
"element": {
"accountDepositType": "NA",
"accountNumber": "NA",
"accountHolderType": "NA"
}
}
]
}
}
```

**"list"** and **"element"** is metadata or type information if you like and it should not appear in output.

Can you please fix that ?

**Reporter**: [Dumitru Husleag](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=dumitru21)

_{**Note**: *This issue was originally created as [PARQUET-1956](https://issues.apache.org/jira/browse/PARQUET-1956). Please see the [migration documentation](https://issues.apache.org/jira/browse/PARQUET-2502) for further details.*}

从 parquet-tools cat -j 命令及其帮助文本开始，然后跟踪嵌套列表数据在 JSON 输出中的呈现方式。使用 issue 中的示例结构，验证列表和元素包装器被省略，同时 account 字段保持不变。完成的标准是：输出包含数据，但不包含这些元数据或类型信息节点。

由索引模型根据 Issue 内容生成。