🚀 Add PID controller 🎉 (backport #434, #975, #899, #1084, #951)

[mergify[bot]]

Proposal for a new controller that provides PID functionality.

The controller can be used stand-alone, in a chain. Measured states can be provided through the topic or state interface, depening on the concrete control arch. For example, if you are having an external estimator, using topic might be eaiser at first then full integration into ros2_control.

The PR depends the following changes:

• ros-controls/control_msgs#69
• ros-controls/control_toolbox#129

Looking forward for your feedback!

Testing dependencies:

  control_msgs:
    type: git
    url: git@github.com:ros-controls/control_msgs.git
    version: add-generic-msgs-for-controller-references
  control_toolbox:
    type: git
    url: git@github.com:ros-controls/control_toolbox.git
    version: add-option-to-define-prefix-as-param-prefix
  ros2_controllers:
    type: git
    url: git@github.com:StoglRobotics-forks/ros2_controllers.git
    version: add-pid-controller

---

This is an automatic backport of pull request #434 done by Mergify.

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 84.28875% with 74 lines in your changes missing coverage. Please review.

Project coverage is 86.75%. Comparing base (94149be) to head (0f77bc3). Report is 2 commits behind head on iron.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## iron #1163 +/- ## ========================================== + Coverage 86.67% 86.75% +0.08% ========================================== Files 86 91 +5 Lines 7412 7831 +419 Branches 612 687 +75 ========================================== + Hits 6424 6794 +370 - Misses 759 791 +32 - Partials 229 246 +17 ``` | [Flag](https://app.codecov.io/gh/ros-controls/ros2_controllers/pull/1163/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=ros-controls) | Coverage Δ | | |---|---|---| | [unittests](https://app.codecov.io/gh/ros-controls/ros2_controllers/pull/1163/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=ros-controls) | `86.75% <84.28%> (+0.08%)` | :arrow_up: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=ros-controls#carryforward-flags-in-the-pull-request-comment) to find out more. | [Files](https://app.codecov.io/gh/ros-controls/ros2_controllers/pull/1163?dropdown=coverage&src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=ros-controls) | Coverage Δ | | |---|---|---| | [pid\_controller/test/test\_load\_pid\_controller.cpp](https://app.codecov.io/gh/ros-controls/ros2_controllers/pull/1163?src=pr&el=tree&filepath=pid_controller%2Ftest%2Ftest_load_pid_controller.cpp&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=ros-controls#diff-cGlkX2NvbnRyb2xsZXIvdGVzdC90ZXN0X2xvYWRfcGlkX2NvbnRyb2xsZXIuY3Bw) | `100.00% <100.00%> (ø)` | | | [pid\_controller/test/test\_pid\_controller.cpp](https://app.codecov.io/gh/ros-controls/ros2_controllers/pull/1163?src=pr&el=tree&filepath=pid_controller%2Ftest%2Ftest_pid_controller.cpp&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=ros-controls#diff-cGlkX2NvbnRyb2xsZXIvdGVzdC90ZXN0X3BpZF9jb250cm9sbGVyLmNwcA==) | `100.00% <100.00%> (ø)` | | | [...\_controller/test/test\_pid\_controller\_preceding.cpp](https://app.codecov.io/gh/ros-controls/ros2_controllers/pull/1163?src=pr&el=tree&filepath=pid_controller%2Ftest%2Ftest_pid_controller_preceding.cpp&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=ros-controls#diff-cGlkX2NvbnRyb2xsZXIvdGVzdC90ZXN0X3BpZF9jb250cm9sbGVyX3ByZWNlZGluZy5jcHA=) | `100.00% <100.00%> (ø)` | | | [pid\_controller/test/test\_pid\_controller.hpp](https://app.codecov.io/gh/ros-controls/ros2_controllers/pull/1163?src=pr&el=tree&filepath=pid_controller%2Ftest%2Ftest_pid_controller.hpp&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=ros-controls#diff-cGlkX2NvbnRyb2xsZXIvdGVzdC90ZXN0X3BpZF9jb250cm9sbGVyLmhwcA==) | `83.14% <83.14%> (ø)` | | | [pid\_controller/src/pid\_controller.cpp](https://app.codecov.io/gh/ros-controls/ros2_controllers/pull/1163?src=pr&el=tree&filepath=pid_controller%2Fsrc%2Fpid_controller.cpp&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=ros-controls#diff-cGlkX2NvbnRyb2xsZXIvc3JjL3BpZF9jb250cm9sbGVyLmNwcA==) | `70.79% <70.79%> (ø)` | | ... and [8 files with indirect coverage changes](https://app.codecov.io/gh/ros-controls/ros2_controllers/pull/1163/indirect-changes?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=ros-controls)