Set up up ros2_control

[Achllle]

Description

Replace our own control code with ros2_control since that's the recommended way to do it, runs fast in c++ and enables using the same interface for simulation systems such as Gazebo. This is no small effort.

Depends on #170 or other means to get a robot_description package.

Resources

• ros 2 control documentation for a general intro to ros2_control
• Ackermann steering controller: this controller would have to be modified (and contributed back?) to support a 6-wheeled version.
• roscon '22 workshop on ros2_control: tutorial
• ros2_control boilerplate pkg: starting point