- Add Dataset_PEMS and Dataset_Solar classes for PEMS and Solar datasets
- Update data_factory.py to include new dataset mappings
- Fix M4 dataset handling with proper numpy array dtype
- Add PEMS-specific loss function (L1Loss) and inverse transform support
- Update validation logic for PEMS dataset with inverse scaling
- Fix M4 data loader insample mask calculation bug
Changes support new traffic and solar energy datasets while maintaining
backward compatibility with existing datasets.
