Feature/config param rotate camera

Related issue https://gitlab.com/sat-metalab/internships/2022-EliesJurquet-LiveposeAvatars/-/issues/52

Rotate camera

---

Rotate images clockwise around their center for all cameras. Ideal for use with vertically tilted webcams. Its default value is 0.
Values that can be passed as parameter are 0, 90, 180 and 270.

Example:

{
  "cameras": {
    "input_paths": ["/dev/video0"],
    "rotate_camera": 90
  }
}