[#61] fix undefined behavior in string

[elfenpiff]

Notes for Reviewer

Just turn FixedSizeByteString::new_unchecked into a non-const function. As it turned out, it had some impact to the concept layer.

Pre-Review Checklist for the PR Author

1. Add sensible notes for the reviewer
2. PR title is short, expressive and meaningful
3. Relevant issues are linked
4. Every source code file has a copyright header with SPDX-License-Identifier: Apache-2.0 OR MIT
5. Branch follows the naming format (iox2-123-introduce-posix-ipc-example)
6. Commits messages are according to this guideline
   • Commit messages have the issue ID ([#123] Add posix ipc example)
   • Commit author matches Eclipse Contributor Agreement (and ECA is signed)
7. Tests follow the best practice for testing
8. Changelog updated in the unreleased section including API breaking changes
9. Assign PR to reviewer
10. All checks have passed (except task-list-completed)

Checklist for the PR Reviewer

• Commits are properly organized and messages are according to the guideline
• Unit tests have been written for new behavior
• Public API is documented
• PR title describes the changes

Post-review Checklist for the PR Author

1. All open points are addressed and tracked via issues

References

Use either 'Closes #123' or 'Relates to #123' to reference the corresponding issue.

Closes #61

[codecov]

Codecov Report

Attention: 5 lines in your changes are missing coverage. Please review.

Comparison is base (c3622ca) 77.97% compared to head (7d027b3) 78.02%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #62      +/-   ##
==========================================
+ Coverage   77.97%   78.02%   +0.05%     
==========================================
  Files         172      172              
  Lines       18734    18782      +48     
==========================================
+ Hits        14607    14655      +48     
  Misses       4127     4127              

Files	Coverage Δ
iceoryx2-bb/container/src/byte_string.rs	90.65% <100.00%> (-0.31%)	⬇️
iceoryx2-bb/container/src/semantic_string.rs	81.28% <100.00%> (ø)
...yx2-cal/src/communication_channel/message_queue.rs	78.92% <100.00%> (ø)
iceoryx2-cal/src/communication_channel/mod.rs	53.84% <100.00%> (+13.84%)	⬆️
...l/src/communication_channel/posix_shared_memory.rs	82.95% <100.00%> (+1.70%)	⬆️
...yx2-cal/src/communication_channel/process_local.rs	84.84% <100.00%> (ø)
...yx2-cal/src/communication_channel/unix_datagram.rs	71.09% <100.00%> (ø)
iceoryx2-cal/src/dynamic_storage/mod.rs	100.00% <100.00%> (ø)
...yx2-cal/src/dynamic_storage/posix_shared_memory.rs	93.36% <100.00%> (ø)
iceoryx2-cal/src/dynamic_storage/process_local.rs	95.18% <100.00%> (ø)
... and 19 more