fdsreader Module, DEVC data and meta information

In the section [fdsreader Module](https://github.com/FireDynamics/LectureFireSimulation/blob/8b1f6f71e2891dc4e33020b688bae29c7c807863/book/content/tools/03_analysis/02_fdsreader.ipynb), I get the following error message with fdsreader `1.2.1`

```python
---------------------------------------------------------------------------
AttributeError Traceback (most recent call last)
in
1 for i in devc:
----> 2 print(f"ID: {devc[i].id},\t quantity: {devc[i].quantity.quantity},\t position: {devc[i].position}")

AttributeError: 'Quantity' object has no attribute 'quantity'
```

for

```python
for i in devc:
print(f"ID: {devc[i].id},\t quantity: {devc[i].quantity.quantity},\t position: {devc[i].position}")
```

Shouldn't it be?
```python
for i in devc:
print(f"ID: {devc[i].id},\t quantity: {devc[i].quantity.name},\t position: {devc[i].position}")
```

打开 book/content/tools/03_analysis/02_fdsreader.ipynb 并检查 fdsreader Module 部分。使用 fdsreader 1.2.1 运行所示的 DEVC 循环以复现 AttributeError，然后验证修正后的元数据表达式是否能在没有错误的情况下生成预期的量信息。

由索引模型根据 Issue 内容生成。