auto_generate_hfss_region method is missing arguments to set minimal region size and region padding.

### 🔍 Before submitting the issue

- [x] I have searched among the existing issues
- [x] I am using a Python virtual environment

### 🐞 Description of the bug

auto_generate_hfss_region method is missing arguments to set minimal region size and region padding.

### 📝 Steps to reproduce

NA

### 💻 Which operating system are you using?

Windows

### 📀 Which ANSYS version are you using?

_No response_

### 🐍 Which Python version are you using?

3.9

### 📦 Installed packages

```shell
all
```

Locate the auto_generate_hfss_region method and inspect its current signature and behavior. Add support for configuring the minimal region size and region padding, then verify that callers can provide both values and that the generated HFSS region reflects them.

Written by the indexing model from the issue text.