Rework calibration process

Allow an entirely separate work flow on the vision node for calibration. First, allow intrinsic and extrinsic to be done separately and allow intrinsics to be done for one camera at a time with the option to just copy the intrinsics of one camera to all nodes since it should be the same.

For alignment: Use a calibration pattern stuck to a wall at a known distance and level. Print big fat numbers on the screen to say the current tilt of the camera and how far the screen centre is from the centre of the chessboard pattern. If square size is known we should be able to display a mm value and attempt to get this as close to half of known baseline as we can.

Stereo calib can then operate separately on now near perfectly lens corrected images that are well aligned.