Add hide labels/confidence

[aphilas]

Add option to hide labels/confidence.

Discussion: #839

Changes:

• sahi/utils/cv.py
  • visualize_prediction() - add hide_labels argument
  • visualize_object_predictions() - add hide_labels and hide_conf arguments
• sahi/predict.py - predict() - add visual_hide_labels and visual_hide_conf arguments
• sahi/prediction.py
  • PredictionResult.export_visuals() - add hide_labels and hide_conf arguments

Demo notebook

I can't find any references for visualize_prediction. Is it used anywhere?

The naming for the arguments is taken from ultralytics/yolov5: utils/detect.py#L172, segment/predict.py#L192