Iox #14 restrict access to chunk header

[elBoberido]

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 restricts the write access to the ChunkHeader only to the ChunkSender. Everyone else has only read access. This prevents accidentally corrupting the ChunkHeader by e.g. setting the payload offset.

Additionally const correctness is added to some methods of the ChunkHeader and the C API is adjusted accordingly

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

• Partly closes Reserved chunkinfo user payload header #14

[codecov]

Codecov Report

Merging #664 (72aaabc) into master (c043d3c) will increase coverage by 0.35%.
The diff coverage is 98.21%.

@@            Coverage Diff             @@
##           master     #664      +/-   ##
==========================================
+ Coverage   74.04%   74.39%   +0.35%     
==========================================
  Files         319      319              
  Lines       11180    11207      +27     
  Branches     1963     1963              
==========================================
+ Hits         8278     8338      +60     
+ Misses       2132     2098      -34     
- Partials      770      771       +1     

Flag	Coverage Δ
unittests	74.35% <98.21%> (+0.35%)	⬆️
unittests_timing	31.20% <19.64%> (-0.06%)	⬇️

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

Impacted Files	Coverage Δ
...nclude/iceoryx_dds/internal/gateway/iox_to_dds.inl	62.96% <0.00%> (ø)
...eoryx_posh/include/iceoryx_posh/popo/publisher.hpp	100.00% <ø> (ø)
...sh/include/iceoryx_posh/popo/untyped_publisher.hpp	100.00% <ø> (ø)
iceoryx_binding_c/source/c_chunk.cpp	100.00% <100.00%> (ø)
...clude/iceoryx_posh/internal/mepoo/chunk_header.inl	100.00% <100.00%> (ø)
...osh/internal/popo/building_blocks/chunk_sender.inl	96.77% <100.00%> (ø)
...h/include/iceoryx_posh/internal/popo/publisher.inl	100.00% <100.00%> (ø)
...lude/iceoryx_posh/internal/popo/sample_deleter.inl	100.00% <100.00%> (ø)
.../include/iceoryx_posh/internal/popo/subscriber.inl	80.00% <100.00%> (ø)
...e/iceoryx_posh/internal/popo/untyped_publisher.inl	100.00% <100.00%> (ø)
... and 6 more

[mossmaurice]

Nitpick: I try to avoid NonConstFoo and ConstFoo. I prefer Foo and ConstFoo

[elBoberido]

I try to be explicit since this tests are explicitly for the constness