Add Ring, Azimuth and Distance fields to published PointCloud

[Robotics010]

carla_ros_bridge doesn't provide ring, azimuth and distance fields in a PointCloud message, so ring_outlier_filter node can not filter a pointcloud. It is needed to find a proper way to add ring, azimuth and distance fields to published PointCloud.

[Robotics010]

It looks like azimuth and distance can be computed from x, y and z as described here

[Robotics010]

Ring is a number of the channel from a laser array but it should be pasted from simulator. Or we can derive it if there is an order of rings maintained and there are no missed points.

[Robotics010]

Adding the ring and timestamp field have been discussed earlier:

• as from carla-ros-bridge (issue_416, pr_431 and pr_432)
• as from carla (issue_5490)