Parameterized Launch Configurations

[jcarpinelli-bdai]

Right now, the franka_bringup package has launch files which load a static controllers.yaml file, which has all of the *_example_controller controllers. I think it would be helpful to have a parameter that defaults to the controllers.yaml file in the franka_bringup package. This way, users could benefit from using franka_bringup, while still loading their own controllers.

If this capability isn't added, I think users have to execute ros2 param set commands as shell processes, either in launch files or manually in a terminal.

@BarisYazici do you agree that a controller_manager_parameters parameter, which defaults to controllers.yaml, is acceptable? If so, I can submit a PR with this change.