Add YOLOv7

[medphisiker]

🚀 Feature

Is your feature request related to a problem? Please describe.
Unfortunately, I do not know if there will be problems with integrating code from this repository link

Describe the solution you'd like
There is a very cool repository with YOLOv7 link. It will be very cool if you append YOLOV7. According to the rating of neural networks-detectors for real time link, YOLOv7 is the best.

Describe alternatives you've considered
I think the alternative is YOLOv5, which is already in your framework. Or we just can use YOLOv7 separately.

Additional context
This neural network is also perfectly ported to ONNX and TensorRT. The creator already provides a convenient class for the inference of this neural network converted to TensorRT link.