[#458] handle stale shm state files on windows

[elfenpiff]

Notes for Reviewer

On Windows we have to create additional shm state files to track the size of the shared memory. When a process dies, those files keep living - but the shared memory is removed by the OS. So when another instance wants to create a shared memory with the same name, then it thinks it already exists since the stale state file is still around.

With this adjustments, the state file create function checks if the shm is actually present, if not, it deletes the old state file and creates a new one which fixes the issue.

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

Relates to eclipse-iceoryx#458