CIFAR10LoaderCommon
Abstract base class for CIFAR-10 loaders that implements common functionality.
CIFAR-10 binary format:
Each image is stored as: 1 byte label + 3072 bytes pixel data
Pixel data is in channel-first format: 1024 red + 1024 green + 1024 blue
Training data is split across 5 batch files (10,000 images each)
Test data is in a single batch file (10,000 images)