[#604] Introduce libc platform

[elBoberido]

Notes for Reviewer

This PR completes to platform abstraction based on the libc crate. Currently it is hidden behind the libc_platform feature flag and currently only works only on Linux. In theory it should be possible to base other platforms than Linux on the libc crate but that's something for the future.

The feature flag can currently also only be used with cargo and cmake. I'm not quite sure how hard it would be to support both, the libc platform and the bindgen generated one, at the same time.

Pre-Review Checklist for the PR Author

• Add sensible notes for the reviewer
• PR title is short, expressive and meaningful
• Consider switching the PR to a draft (Convert to draft)
  • as draft PR, the CI will be skipped for pushes
• Relevant issues are linked in the References section
• Every source code file has a copyright header with SPDX-License-Identifier: Apache-2.0 OR MIT
• Branch follows the naming format (iox2-123-introduce-posix-ipc-example)
• 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)
• Tests follow the best practice for testing
• Changelog updated in the unreleased section including API breaking changes
• Assign PR to reviewer
• 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

• All open points are addressed and tracked via issues

References

Closes #604

[codecov]

Codecov Report

Attention: Patch coverage is 64.70588% with 18 lines in your changes missing coverage. Please review.

Project coverage is 79.07%. Comparing base (5e0edcd) to head (8fc2723).
Report is 6 commits behind head on main.

Files with missing lines	Patch %	Lines
iceoryx2-pal/posix/src/linux/signal.rs	43.33%	17 Missing ⚠️
iceoryx2-bb/posix/src/signal.rs	80.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #614      +/-   ##
==========================================
- Coverage   79.19%   79.07%   -0.12%     
==========================================
  Files         200      200              
  Lines       24124    24156      +32     
==========================================
- Hits        19105    19102       -3     
- Misses       5019     5054      +35     

Files with missing lines	Coverage Δ
iceoryx2-pal/posix/src/lib.rs	58.82% <ø> (ø)
iceoryx2-pal/posix/src/linux/fcntl.rs	96.00% <100.00%> (ø)
iceoryx2-pal/posix/src/linux/pthread.rs	95.10% <100.00%> (+0.28%)	⬆️
iceoryx2-pal/posix/src/linux/stat.rs	100.00% <100.00%> (ø)
iceoryx2-pal/posix/src/linux/types.rs	100.00% <100.00%> (ø)
iceoryx2-bb/posix/src/signal.rs	74.43% <80.00%> (-0.29%)	⬇️
iceoryx2-pal/posix/src/linux/signal.rs	45.16% <43.33%> (-54.84%)	⬇️

... and 9 files with indirect coverage changes