fix: add absolute tarfile test, windows workaround

[terriko]

This adds a tarfile with an absolute path file in it for testing, and tweaks behaviour on windows so it will use an external tar program to extract to a specified directory if such a program is available.

[terriko]

Note for self: the linux tests are failing even on main and need investigation but there's no new failures here. My attempt at a windows fix is causing all the windows tests that use extraction to fail, though, so that's clearly not working and needs adjustment (although the short-term adjustment may be "make sure tar is installed and we can find it" rather than in this code)

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 66.66667% with 8 lines in your changes are missing coverage. Please review.

Project coverage is 80.37%. Comparing base (d6cbe40) to head (b1f0d13).
Report is 106 commits behind head on main.

Files	Patch %	Lines
cve_bin_tool/extractor.py	57.89%	5 Missing and 3 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3849      +/-   ##
==========================================
+ Coverage   75.41%   80.37%   +4.95%     
==========================================
  Files         808      820      +12     
  Lines       11983    12371     +388     
  Branches     1598     1676      +78     
==========================================
+ Hits         9037     9943     +906     
+ Misses       2593     2004     -589     
- Partials      353      424      +71     

Flag	Coverage Δ
longtests	80.37% <66.66%> (+4.95%)	⬆️

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[terriko]

Current setup (running local tar/7z on windows) is passing 98% of tests and then timing out., so I'm upping the windows timeouts to see if it actually can complete to inform what we do next.

[terriko]

Still stopped at 98% with higher limit, so there's a coding issue that's causing this rather than just a timeout.

[terriko]

Closing this in favour of a new PR with only the windows experiment in it.