Rework baselines & Add datasets

What's Changed

• Rework baselines to increase code reuse and simplify their use.
• Add post-hoc temperature scaling
• Add ImageNet variations (A, O, R)
• Add dataset autodownload
• Add transforms for PixMix.
• Update packages

Pull Requests

• Rework baselines by @alafage in #25
• Merge dev in main ✨ by @o-laurent in #24

Full Changelog: v0.1.1...v0.1.2