Integrate the new LiDAR system

[onkoe]

Goal

Connect Nav2 to the new LiDAR system.

Summary

We're replacing our depth camera with LiDAR! We can safely rip out the zed package we created and replace it with lidar or something similar.

LiDAR requires much less processing power to get useful results, and the processing is much more accessible, too. A lot less code is required.

Checklist

Complete all these sub-tasks to complete this issue!

(these steps will probably change a bit when we get the actual LiDAR unit in hand)

• Vendor the unilidar_sdk into our repo
  • Clone it and make it not a repo: cd src/ && git clone https://github.com/unitreerobotics/unilidar_sdk && cd unilidar_sdk && rm -rfd .git
  • Remove all references to Windows
  • Remove ROS 1 stuff
• Configure Nav2 to use the sensor_msgs::msg::PointCloud2 that the unitree_lidar_ros2::unitree_lidar_ros2_node creates
• Replace the simulator's depth camera with a LiDAR unit
  • YEEEEEEES I'VE BEEN WAITING FOR THIS
• Test + iterate until it works on the simulator
• Test + iterate until it works on the Rover ;D