iox-1391 move filesystem files to separate module

[FerdinandSpitzschnueffler]

Pre-Review Checklist for the PR Author

1. Code follows the coding style of CONTRIBUTING.md
2. Tests follow the best practice for testing
3. Changelog updated in the unreleased section including API breaking changes
4. Branch follows the naming format (iox-123-this-is-a-branch)
5. Commits messages are according to this guideline
   • Commit messages have the issue ID (iox-#123 commit text)
   • Commit author matches Eclipse Contributor Agreement (and ECA is signed)
6. Update the PR title
   • Follow the same conventions as for commit messages
   • Link to the relevant issue
7. Relevant issues are linked
8. Add sensible notes for the reviewer
9. All checks have passed (except task-list-completed)
10. All touched (C/C++) source code files from iceoryx_hoofs are added to ./clang-tidy-diff-scans.txt
11. Assign PR to reviewer

Notes for Reviewer

See PR title.

Checklist for the PR Reviewer

• Commits are properly organized and messages are according to the guideline
• Code according to our coding style and naming conventions
• Unit tests have been written for new behavior
• Public API changes are documented via doxygen
• Copyright owner are updated in the changed files
• All touched (C/C++) source code files from iceoryx_hoofs have been added to ./clang-tidy-diff-scans.txt
• PR title describes the changes

Post-review Checklist for the PR Author

1. All open points are addressed and tracked via issues

References

• Closes Split iceoryx_hoofs into logical modules #1391 (partially)

[codecov]

Codecov Report

Merging #1875 (21b4e32) into master (f4c81ab) will decrease coverage by 0.02%.
The diff coverage is 83.33%.

@@            Coverage Diff             @@
##           master    #1875      +/-   ##
==========================================
- Coverage   75.44%   75.42%   -0.02%     
==========================================
  Files         383      383              
  Lines       15173    15173              
  Branches     2148     2148              
==========================================
- Hits        11447    11444       -3     
  Misses       3055     3055              
- Partials      671      674       +3     

Flag	Coverage Δ
unittests	75.08% <83.33%> (-0.02%)	⬇️
unittests_timing	15.44% <0.00%> (+0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...hoofs/filesystem/include/iox/detail/filesystem.inl	100.00% <ø> (ø)
iceoryx_hoofs/filesystem/source/filesystem.cpp	70.14% <ø> (ø)
...lude/iceoryx_posh/internal/mepoo/mepoo_segment.inl	91.83% <ø> (ø)
...posh/roudi/memory/iceoryx_roudi_memory_manager.hpp	12.50% <ø> (ø)
.../source/roudi/memory/posix_shm_memory_provider.cpp	87.50% <ø> (ø)
iceoryx_posh/source/runtime/posh_runtime.cpp	42.00% <0.00%> (ø)
iceoryx_posh/source/runtime/shared_memory_user.cpp	0.00% <ø> (ø)
iceoryx_dust/source/posix_wrapper/named_pipe.cpp	50.73% <66.66%> (ø)
iceoryx_hoofs/source/posix_wrapper/file_lock.cpp	38.35% <66.66%> (ø)
...fs/internal/posix_wrapper/shared_memory_object.hpp	87.50% <100.00%> (ø)
... and 9 more