Move complex examples to own repositories

[emilk]

The examples in the repository should be easy to run on any platform. If they are not, they should be moved to own repositories, with links from this one.

These examples should be moved:

• ros_node
• controlnet (unless we can patch it to work without CUDA)

[Wumpf]

while in the process we should also add a blueprint to ros_node

[emilk]

Remember to use https://github.com/rerun-io/rerun_template/ when setting up the new repositories!