remove exceptions

[koonpeng]

This is a preview of the work in removing exceptions.

Inspired from rust, Result<T> is the alternative to exceptions. Internally it uses std::variant to store either the result or a std::exception.

• [[nodiscard]] should almost always be used when returning Result<T>. We don't have custom lint rules so it will have to be checked manually.
• Result<void> is a special case that using std::optional instead.
• One downside is that we cannot return a reference, Result<T&> does not work because std::variant cannot contain references.
  • In theory should be able to specialize Result<T> for all reference types and store a pointer internally instead.

[koonpeng]

Integration test is working with the latest release of ros2 iron, but the docker images are not updated yet.

[Yadunund]

Could you merge the latest main into the base branch also rebase/update this branch?