[ROS][feat] Create new keypoint extractor using a vertex map

This MR is based on !324 (merged). Please see the description of !324 (merged) for further explanations on commits.

Goal

This MR will implement an idea from !104 (closed) : using a vertex map to extract keypoints.

So far, we were only extracting keypoints looking at their neighborhood on their scanline.

For dense rotative lidar, the scanlines are close enough to each other to build a meaningful image and create 2D neighborhoods.

In this MR, we reproduce SSKE behaviour and improve it along the way. We also fix a few things related to keypoint extractors.

The next goal is to be able to use new criteria related to upper and lower lines. This will belong to another MR.

Results

Reproduce

Config files are identical for keypoint extractors in ros and ros2 wrapping. We tested on a Velodyne 16 pcap, car loop.

Run

roslaunch lidar_slam slam_velodyne.py outdoor:=true use_sim_time:=false pcap:=path/to/pcap/file.pcap velodyne_driver:=true