Ros2 dashing

[vandanamandlik]

@AAlon , Please find first PR for Deep racer application.

Description of changes: Deepracer simulation migration from ROS1 to ROS2

• Modified CMakeLists.txt and package.xml as per ROS2 guidelines.
• Added ROS2 Deep Racer Simulation package dependencies repos to .rosinstall file.
• Added launch file to launch racer car and car track model in gazebo.
• converted .xacro file of car model to sdf file.

Steps to build and test simulation workspace locally:

• First add COLCON_IGNORE empty file at following paths to avoid build error as these packages are not part of this PR.
  • simulation_ws/src/deepracer_interpreter/COLCON_IGNORE
  • simulation_ws/src/deepracer_msgs/COLCON_IGNORE
  • simulation_ws/src/sagemaker_rl_agent/COLCON_IGNORE
• cd simulation_ws
• rosws update
• rosdep install --from-paths src --ignore-src -r -y
• colcon build
• export GAZEBO_MODEL_PATH=$GAZEBO_MODEL_PATH: eg. export GAZEBO_MODEL_PATH=$GAZEBO_MODEL_PATH:/home/root-pc/vandana/ros2/deep_exm_ws/src/deepracer_simulation/models
• export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/lib/x86_64-linux-gnu/gazebo-9/plugins/
• ros2 launch deepracer_simulation racecar_simulation.launch.py

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[vandanamandlik]

Overall LGTM :) last comment from my side below.

Full disclosure- we haven't sufficiently tested this yet so there might be more asks / issues we'll discover later. OK. We will address it if you find any issues. Any estimate on the robot_ws part? There is no robot_ws in deepracer ROS1 package.