Add Troubleshooting for Common QT Issues

- Add a new section in the documentation: *“Troubleshooting PyFluent Visualization in Notebooks and IDEs”*.
- The following may not be accurate or complete (it is LLM generated).
- Include common causes for `ImportError` due to mixed QT bindings.
- Suggest best practices:
- Don’t mix PyQt5 and PySide6.
- Use clean virtual environments.
- Run GUI code outside of IPython if needed.
- How to check current QT backend.
- Include a known-issues section specifically for Spyder, JupyterLab, VSCode.