`LeRobotDataset`: Bringing large-scale datasets to lerobot

The release of LeRobotDataset:v3.0 introduces a new format for large-scale robotics datasets to solve previous file-system limitations. Unlike the prior version which stored one episode per file, v3.0 packs multiple episodes into a single file, using relational metadata for retrieval. This new format also natively supports streaming, allowing for on-the-fly processing of large datasets without needing to download them entirely. LeRobotDataset is a core part of the `lerobot` library, providing a unified interface for multi-modal robotics data that integrates with the PyTorch and Hugging Face ecosystems.