added yolonas coco model inference

[naseemap47]

added yolonas coco model inference

Args

-n, --num: Number of classes the model trained on
-m, --model: Model type (choices: yolo_nas_s, yolo_nas_m, yolo_nas_l)
-w, --weight: path to trained model weight, for COCO model: coco
-s, --source: video path/cam-id/RTSP
-c, --conf: model prediction confidence (0<conf<1)
--save: to save video
--hide: hide video window

Example:

# For COCO YOLO-NAS Model
python3 inference.py --model yolo_nas_s --weight coco --source 0                              # Camera
python3 inference.py --model yolo_nas_m --weight coco --source /test/video.mp4 --conf 0.66    # video