Use defered service support in rclcpp

[ivanpauno]

Replaces https://github.com/ros2/domain_bridge/pull/48.

Multiple inheritance with std::enable_shared_from_this is problematic, see:

• https://stackoverflow.com/questions/16082785/use-of-enable-shared-from-this-with-multiple-inheritance
• https://stackoverflow.com/questions/15549722/double-inheritance-of-enable-shared-from-this
• https://stackoverflow.com/questions/12790859/bad-weak-pointer-when-base-and-derived-class-both-inherit-from-boostenable-sha
• https://stackoverflow.com/questions/14939190/boost-shared-from-this-and-multiple-inheritance

The solutions proposed in those threads cannot directly applied here.

To avoid the issue, I'm using the support for defering responses in services added in rclcpp, avoiding the need of using std::enable_shared_from_this all together. We will need a new branch for rolling though, but I couldn't find a backwards compatible solution.

[jacobperron]

I think the test failures are known flakes and I guess the workflow is failing because it not using the testing repo for Rolling debs. I would go ahead and merge this.

[jacobperron]

See https://github.com/ros2/domain_bridge/pull/50 for switching CI to use the testing repo.

[ivanpauno]

LGTM. The main branch is currently targeting Rolling. We have a separate galactic branch now.

Sounds good! I forgot about that

[jacobperron]

I've rebased this after merging #50.