Add k3 support for onmidir

[GibsDev]

Related to this issue, but with a narrower scope to support adding k3. In some cases k1 and k2 aren't enough.

• cv::omnidir::calibrate and cv::omnidir::stereoCalibrate do not support cv::omnidir::CALIB_USE_GUESS and distortion k3 should be supported #2784