Update Semantic FPN and add Random Crop and Photometric Transforms

[thomasehuang]

This PR updates the Semantic FPN model and adds the Random Crop and Photometric transforms.

• Reproduce Semantic FPN performance:
  • [x] Inference of BDD100K models checkpoint.
  • [x] Training. 59.2 mIoU (Vis4D) vs. 59.2 mIoU (BDD100K model zoo).
• Add transforms:
  • [x] Random crop. Added optional in_keys parsing for transforms, may need to discuss the design.
  • [x] Photometric.
• Add step-based training.
• Update seg mask visualizer.