[Visualizer] support v2 dataset

[mishig25]

Description

As we discussed offline, this PR updates the visualizer to use v2 datasets and merge all the visualizer changes from https://huggingface.co/spaces/lerobot/visualize_dataset fork into lerobot repository

Usage

# start a server with homepage will fetch datasets hosted remotely on hf.co/dataasets
python lerobot/scripts/visualize_dataset_html.py

# start a server with specific dataset (by default it will download parquet & video files locally AND start the visualizer server)
python lerobot/scripts/visualize_dataset_html.py --repo-id lerobot/aloha_static_ziploc_slide

# start a server with specific dataset without downloading parquet & video files locally (instead the visualizer server will fetch the dataset hosted remotely on hf.co/dataasets) `-load-from-hf-hub 1` arg
python lerobot/scripts/visualize_dataset_html.py --repo-id lerobot/aloha_static_ziploc_slide --load-from-hf-hub 1