[#533] Process callbacks in deadline_queue immediately on zero-timeout

[orecham]

Notes for Reviewer

Adds functionality to process all callbacks without waiting when providing a 0 timeout.

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 in the References section
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

Closes #533

[codecov]

Codecov Report

Attention: Patch coverage is 85.71429% with 2 lines in your changes missing coverage. Please review.

Project coverage is 79.12%. Comparing base (949d2e0) to head (56d6d5e).
Report is 51 commits behind head on main.

Files with missing lines	Patch %	Lines
iceoryx2-bb/posix/src/deadline_queue.rs	84.61%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #539      +/-   ##
==========================================
- Coverage   79.13%   79.12%   -0.02%     
==========================================
  Files         202      202              
  Lines       24815    24824       +9     
==========================================
+ Hits        19638    19641       +3     
- Misses       5177     5183       +6     

Files with missing lines	Coverage Δ
iceoryx2/src/port/waitset.rs	81.23% <100.00%> (ø)
iceoryx2-bb/posix/src/deadline_queue.rs	89.03% <84.61%> (-0.70%)	⬇️

... and 8 files with indirect coverage changes

[elfenpiff]

It is just my personal opinion but I would prefer call(DeadlineQueueIndex(attachment.index)) == CallbackProgression::Stop over matches!(call(DeadlineQueueIndex(attachment.index)), CallbackProgression::Stop) just because it is for me just more intuitive.

And also my internal pattern matching in my head has much less to think about a line like if whatever == foo than if matches!(whatever, foo). Especially, when we have to deal with multiple languages like c, c++, rust and soon python or go.

So, I would prefer it the old way but I do not insist.