Add 2D Segmentation Tutorial Using PyTorch Lightning and Weights & Biases to MONAI

[rittik9]

Is your feature request related to a problem? Please describe.
These tutorial aim to reduce boilerplate code while enhancing user experience by providing a clear understanding of how to leverage PyTorch Lightning for structured training processes and W&B for effective monitoring of experiments.

Describe the solution you'd like
A sample notebook for 2D segmentation task utilizing PyTorch Lightning and Weights & Biases (W&B) within the MONAI framework.