Add ament_cmake_clang_tidy to ament_lint_common

[mm318]

Closes #283

This pull request will make ament_clang_tidy one of the default linters that get run during colcon test.

[audrow]

Let me know when this is ready for a review.

Do you think that this will add a bunch of warnings downstream? Would it make sense to run CI for all downstream packages?

[mwcondino]

Is this still being actively worked? I'd be interested in picking it up if not

[mm318]

Sure @mwcondino, any help would be appreciated!

I think this involves more than just turning on clang-tidy though, such as assessing the impact on the building of current packages.

[nuclearsandwich]

I've been doing some work to get clang-tidy running for a subset of ROS packages. An example build from that work is here: https://build.ros2.org/view/Rci/job/Rci__clang-tidy_ubuntu_focal_amd64/6/

Adding additional tools to ament_lint_common will, in my opinion, constitute a major version level change for the ament_lint packages and require a lot of communication to downstream consumers outside of the ROS 2 core.

And regarding the core, I do not think that clang-tidy can be added to ament_lint_common without a massive effort to review and squash existing warnings in the ROS 2 core packages. Some review is happening now and so we can expect some improvement from the state listed in the linked job but I don't think making clang_tidy part of ament_lint_common is likely during the ROS Humble development phase.

However, one of the conflicts this PR currently has is due to #316 which includes the same change in the CMake hook to properly set the script in the CMake build directory. I still have to work with @audrow to coordinate a release of ament_lint but if you're already using ament_lint_common and ament_lint_auto, you can add <test_depend>ament_cmake_clang_tidy</test_depend> and ament_lint_auto should find and hook it just like the linters in ament_lint_common.