fix: get parent folder name portability

[scolladon]

Explain your changes

---

Fix the way we split the path of a line to get the parent folder
Make sure it works on any path.sep environment specificities

Does this close any currently open issues?

---

closes #548

[codeclimate]

Code Climate has analyzed commit 402936e and detected 0 issues on this pull request.

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[codecov]

Codecov Report

Patch coverage: 100.00% and no project coverage change.

Comparison is base (ddd2d5f) 100.00% compared to head (402936e) 100.00%.

Additional details and impacted files

@@            Coverage Diff            @@
##              main      #562   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           31        31           
  Lines          863       862    -1     
=========================================
- Hits           863       862    -1     

Impacted Files	Coverage Δ
src/service/inFolderHandler.js	100.00% <100.00%> (ø)
src/service/inResourceHandler.js	100.00% <100.00%> (ø)

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[github-actions]

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