Use CameraInfo `P` translation to offset camera center

[lucasw]

It looks like the Tx, Ty translations in a CameraInfo are ignored in the camera info rviz display- I think it would only require converting the Txyz (as specified in http://docs.ros.org/en/noetic/api/sensor_msgs/html/msg/CameraInfo.html- it says it assumes Tz is always zero, but if it wasn't zero why not respect it here?) to meters and then shifting the entire set of camera info 3D lines by that amount. I think a negative Tx is a shift to the right (or +x) in camera optical frame but I'd like to double check.

(and now I'm curious if rviz DepthCloud or Camera respects the Tx/Ty either)