Iox #482 add example for complex data types

[FerdinandSpitzschnueffler]

Pre-Review Checklist for the PR Author

1. Code follows the coding style of CONTRIBUTING.md
2. Tests follow the best practice for testing
3. Branch follows the naming format (iox-#123-this-is-a-branch)
4. Commits messages are according to this guideline
   • Commit messages have the issue ID (iox-#123 commit text)
   • Commit messages are signed (git commit -s)
   • Commit author matches Eclipse Contributor Agreement (and ECA is signed)
5. Update the PR title
   • Follow the same conventions as for commit messages
   • Link to the relevant issue
6. Relevant issues are linked
7. Add sensible notes for the reviewer
8. All checks have passed (except task-list-completed)
9. Assign PR to reviewer

Notes for Reviewer

This PR introduces an example for sending/receiving our cxx constructs. The README.md includes only the outline and will be finished once the example code is approved.

Checklist for the PR Reviewer

• Commits are properly organized and messages are according to the guideline
• Code according to our coding style and naming conventions
• Unit tests have been written for new behavior
• Public API changes are documented via doxygen
• Copyright owner are updated in the changed files
• PR title describes the changes

Post-review Checklist for the PR Author

1. All open points are addressed and tracked via issues

References

• Partially closes Improve documentation and website for v2.0 #743

[codecov]

Codecov Report

Merging #716 (a21e6b1) into master (4ce5310) will decrease coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #716      +/-   ##
==========================================
- Coverage   74.03%   74.01%   -0.02%     
==========================================
  Files         319      319              
  Lines       11426    11458      +32     
  Branches     1972     1976       +4     
==========================================
+ Hits         8459     8481      +22     
- Misses       2192     2198       +6     
- Partials      775      779       +4     

Flag	Coverage Δ
unittests	72.82% <100.00%> (-0.01%)	⬇️
unittests_timing	30.44% <0.00%> (-0.06%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...ceoryx_utils/include/iceoryx_utils/cxx/variant.hpp	100.00% <ø> (ø)
...ils/include/iceoryx_utils/internal/cxx/variant.inl	96.84% <100.00%> (ø)
...e/iceoryx_utils/internal/concurrent/smart_lock.inl	92.45% <0.00%> (-7.55%)	⬇️
..._utils/source/posix_wrapper/unix_domain_socket.cpp	57.07% <0.00%> (-1.83%)	⬇️
...nclude/iceoryx_utils/internal/cxx/forward_list.inl	88.26% <0.00%> (-0.78%)	⬇️
...nternal/roudi/introspection/port_introspection.inl	71.89% <0.00%> (-0.73%)	⬇️
..._utils/include/iceoryx_utils/internal/cxx/list.inl	89.35% <0.00%> (-0.69%)	⬇️
iceoryx_posh/source/roudi/roudi.cpp	54.28% <0.00%> (ø)
...ils/include/iceoryx_utils/internal/cxx/smart_c.inl	89.06% <0.00%> (ø)
...e/iceoryx_utils/internal/concurrent/smart_lock.hpp	100.00% <0.00%> (ø)
... and 2 more

[dkroenke]

LGTM, just a nitpick from my side.