Add 'timezone' config support for Db model

#### What are you trying to achieve?
Specific timezone when use Db Model connect to mysql , then the test logic won't rely on database config.
#### What do you get instead?
Can't achieve this for now.
> Provide console output if related. Use `-vvv` mode for more details.

```bash
# paste output here
```
> Provide test source code if related

```php
// paste test
```
### Details

* Codeception version:
* PHP Version:
* Operating System:
* Installation type: Phar || Composer
* List of installed packages (`composer show`)
* Suite configuration:

```yml
# paste suite config here
```

首先定位 Db 模型的 MySQL 連線設定，以及目前依賴資料庫時區設定的測試。確定套件設定如何傳遞給模型，然後定義時區選項，並驗證測試可以選擇特定時區，而不必依賴資料庫的全域設定。

由索引模型根據 Issue 內容生成。