[#390] event based comm example cpp

[elfenpiff]

Notes for Reviewer

Ports the rust event_based_communication example to C++.

Additionally, introduce FileDescriptorBased and implement it for FileDescriptorView so that WaitSet::attach_**() can be handled easier and the user does not have to acquire low-level implementation details like the file descriptor.

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 #390

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 78.82%. Comparing base (3d5f942) to head (4b68d49).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #524      +/-   ##
==========================================
- Coverage   78.88%   78.82%   -0.06%     
==========================================
  Files         201      201              
  Lines       24220    24220              
==========================================
- Hits        19106    19092      -14     
- Misses       5114     5128      +14     

see 3 files with indirect coverage changes