Fixes #1938

Description

Notebook tutorial to demonstrate the suggested solution for wrapping nnUNet into a MONAI Bundle (Project-MONAI/MONAI#8328)

The notebook includes code to:

1. Train a nnUNet model using the nnUNetV2Runner implementation
2. Wrap the trained model into a MONAI Bundle-compatible model
3. Run Inference using the MONAI Bundle syntax
4. Instructions on how to generate the MONAI Bundle to run the nnUNet training step with the MONAI Bundle syntax.

Checks

• Avoid including large-size files in the PR.
• Clean up long text outputs from code cells in the notebook.
• For security purposes, please check the contents and remove any sensitive info such as user names and private key.
• Ensure (1) hyperlinks and markdown anchors are working (2) use relative paths for tutorial repo files (3) put figure and graphs in the ./figure folder
• Notebook runs automatically ./runner.sh -t <path to .ipynb file>