Add demo.launch.py for ros2

[vatanaksoytezer]

Most of the tutorials depends on demo.launch.py of panda_moveit_config. This PR adds this file along with rviz2 configs, so it can be used by tutorials.

[MarqRazz]

@vatanaksoytezer why did the rviz configs change? Are the changes compatible with ROS1 & 2?

[vatanaksoytezer]

@vatanaksoytezer why did the rviz configs change? Are the changes compatible with ROS1 & 2?

rviz configurations are not compatible between ROS1 and ROS2 so I had to make a new ROS2 config.

[MarqRazz]

If that is the case should we delete demo.launch? I know the rest of the launch files are not working but we should probably delete the ones that have been converted.

[vatanaksoytezer]

If that is the case should we delete demo.launch? I know the rest of the launch files are not working but we should probably delete the ones that have been converted.

I was questioning that myself as well. I just left it as a reference but since it is converted it makes sense to delete it. I'll delete it.