Implements the creation of ReID transformer dataset creation for PyTorch pose estimation models.

• implements deeplabcut.create_tracking_dataset for PyTorch models
  • Closes np.nanmean bug in creating triplets for transformer re-ID: query_feature_by_coord_in_img_space() function #2794
  • Closes Unsupervised ID tracking - This function is not implemented for Engine.PYTORCH #2809
  • Creates a FeatureShelfWriter to save ReID features

Other changes

• removes the dynamic parameter from deeplabcut.create_tracking_dataset as it cannot be used there
• adds a docstring for deeplabcut.create_tracking_dataset
• correctly pulls the pcutoff from the inference config when creating assemblies in convert_detections2tracklets
• adds an image_size key to the context when running inference, and a top_down_crop_size for top-down models