Update default sim to use AMP kart

[alanssitis]

Description

Update default sim to use AMP kart instead of tb3 waffle robot.

Tasks

• [ ] Remove waffle robot
• [ ] Add AMP kart URDF model
• [ ] Add AMP kart Gazebo model
• [ ] Add AMP kart Gazebo model to sim

Resources

• https://docs.ros.org/en/foxy/Tutorials/Intermediate/URDF/URDF-Main.html

[alanssitis]

Fixed a while back I think