Fix parameter library export

[tylerjw]

@fmauch

This PR is directed towards fixing the issue experienced by ur_controllers in this PR: #446

In my local testing the changes in #446 did not cuase the ur_controllers code to complete building, it did get it further than the error experienced in the buildfarm.

Instead of using the parameters.xml to export the transitive dependency of parameter_traits from the parmaeter library this updates the cmake to export the generated pareamters library and export a dependency on generate_parameter_library which exports the dependency on parameter_traits in addition to a handful of other dependencies of the parameters interface.

I tested this by building the following workspace on Rolling.

repositories:
  Universal_Robots_ROS2_Driver:
    type: git
    url: https://github.com/UniversalRobots/Universal_Robots_ROS2_Driver.git
    version: main
  control_msgs:
    type: git
    url: https://github.com/ros-controls/control_msgs.git
    version: humble
  cpp_polyfills:
    type: git
    url: https://github.com/PickNikRobotics/cpp_polyfills.git
    version: main
  generate_parameter_library:
    type: git
    url: https://github.com/PickNikRobotics/generate_parameter_library.git
    version: main
  realtime_tools:
    type: git
    url: https://github.com/ros-controls/realtime_tools.git
    version: master
  ros2_control:
    type: git
    url: https://github.com/ros-controls/ros2_control.git
    version: master
  ros2_controllers:
    type: git
    url: https://github.com/tylerjw/ros2_controllers.git
    version: fix_gpl_export

For reference on the cmake changes for exporting libraries I used this: https://docs.ros.org/en/rolling/How-To-Guides/Ament-CMake-Documentation.html#building-a-library

Recently I went through fixing a bunch of my other library code and had to learn how all this works again.

[fmauch]

This looks quite sane, but I'm unsure how to actually test that locally, since the problem only occurred on the buildfarm when the JTC was installed as binary package. As the dependencies would have been installed already, if we built ros2_controllers from source on the same machine, this would not be quite the same test.

[tylerjw]

I was able to build from source locally and that produced the same failure as in the logs in the buildfarm. I built using colcon with this command:

colcon build --mixin ccache rel-with-deb-info lld shared compile-commands

I believe the way colcon builds each package with an isolated build is really similar to how the buildfarm builds debian packages. I could be wrong about this, maybe others know a better way of testing this?

[fmauch]

I build my workspace locally and it builds fine also without the change introduced here. However, we experienced problems with ccache also in our CI pipeline when migrating the API to the parameter interface, see this commit and this failing pipeline before disabling the cache.

That's why I am rather certain that it should not be a matter of building everything from source, but the problem is actually the dependency simply not being installed, as it was only a build dependency. As this PR adds generate_parameter_library as a full dependency to the JTC package, I am almost 100% certain that this should fix the issue on the buildfarm, as well.

[tylerjw]

As this PR adds generate_parameter_library as a full dependency to the JTC package

I wanted to do it this way because the library generated has more dependencies than parameter_traits and adding parameter_traits as a dependency only gets the build a little further and it breaks on the next dependency.

[destogl]

Thanks for updating this!

[destogl]

@tylerjw It's OK that some builds are failing (unfortunately). We have to get kinematics_interface package merged.