Publish the webots point cloud data to ROS2

[SenHe524]

Publish the point cloud data simulated by webots in ros2, and then check the specific data of the point cloud through rqt. It reads as follows:

I wonder why this is happening? And what's that extra 8 bytes of data? After I parse the data out, it takes the following form:

I think the data in the red box is the x, y and z coordinates of the points, and the data in the blue box is the two additional unknown data.
@ManuelZ @brettle @Olegas @sgvandijk @correll