Fix unzip bug

[fpseverino]

• Fix a bug where unzipped files were empty
• Add testing to avoid such issue in the future

[codecov]

Codecov Report

Attention: Patch coverage is 90.00000% with 1 line in your changes missing coverage. Please review.

Project coverage is 96.14%. Comparing base (5ca8997) to head (d00d1ea).
Report is 1 commits behind head on main.

Files	Patch %	Lines
Sources/Zip/Zip.swift	90.00%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main       #7   +/-   ##
=======================================
  Coverage   96.14%   96.14%           
=======================================
  Files           7        7           
  Lines         337      337           
=======================================
  Hits          324      324           
  Misses         13       13           

Files	Coverage Δ
Sources/Zip/Zip.swift	93.36% <90.00%> (ø)

[MahdiBM]

I can't say I fully understood what's going on in those c functions, but considering there are tests I'll approve this. Feel free to merge or wait for someone else to review as well 🙂.