[script.*] Change prediction to write dataset predictions on a subfolder named after the dataset name in the current run

[models,configs/models] Cleanup model implementation to re-use all backbones from torchvision; Simplify checkpointer; Remove own implementation of model_zoo; Implement normalization for torchvision-based backbones; Enables pytorch installation on osx

[docs,scripts] Separate evaluation script; Improve trainer engine code; Reset network model names to match resource names