opencv: new cameracalibrate and cameraundistort elements

Submitted by Philippe Renon

Link to original bug (#789075)

Description

The two new elements are based on this OpenCV tutorial : Based on this tutorial: https://docs.opencv.org/2.4/doc/tutorials/calib3d/camera_calibration/camera_calibration.html

In a nutshell:

The cameracalibrate elements takes an operator through a camera calibration procedure. The operator presents a calibration pattern to the camera for multiple detections. See the photos at the end of the tutorial to get a glimpse of what it looks like. This procedure can be CPU intensive while it is in progress. All the processing is done inline (can stall the pipeline at times).

The cameraundistort uses the results of the calibration to correct the camera images. In that process some pixels will be lost and the images will be scaled up.
It is basically a transform element and CPU usage is moderate.

Version: 1.12.3