[#547] Move waitset into main iox2 namespace

[elfenpiff]

Notes for Reviewer

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 #547

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 79.18%. Comparing base (ad49e19) to head (dbc22d6).
Report is 4 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #548      +/-   ##
==========================================
+ Coverage   79.12%   79.18%   +0.05%     
==========================================
  Files         203      203              
  Lines       25132    25132              
==========================================
+ Hits        19885    19900      +15     
+ Misses       5247     5232      -15     

Files with missing lines	Coverage Δ
iceoryx2/src/port/mod.rs	0.00% <ø> (ø)
iceoryx2/src/waitset.rs	81.23% <ø> (ø)

... and 9 files with indirect coverage changes