Refactor zip filesystem

[Schamper]

As a follow up to #1772, this PR aims to simplify and speed up the zip filesystem implementation a bit by getting rid of the dependency of the virtual filesystem, as well as hopefully dealing with some more edge cases.

I took some inspiration from how zipfile.ZipPath works for this.

Correctly dealing with all the paths and variations is a bit tricky, so I'm sure there's room for improvement. This is also a bit of a test run before I commit to the tar variant, since that has a lot of loaders that depend on the implementation details of the current tar filesystem.

Fingers crossed that Codspeed agrees this is faster.

[codspeed-hq]

Merging this PR will degrade performance by 11.54%

⚡ 1 improved benchmark
❌ 8 regressed benchmarks
✅ 23 untouched benchmarks

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Benchmark	BASE	HEAD	Efficiency
❌	test_benchmark_zip_filesystem[absolute-base-dir]	90.6 ms	110.1 ms	-17.77%
❌	test_benchmark_zip_filesystem[absolute-base]	90.6 ms	109.9 ms	-17.55%
❌	test_benchmark_zip_filesystem[base]	90.6 ms	109.1 ms	-16.95%
❌	test_benchmark_zip_filesystem[relative]	91.2 ms	108 ms	-15.6%
❌	test_benchmark_zip_filesystem[relative-dir]	91.1 ms	107.8 ms	-15.46%
❌	test_benchmark_zip_filesystem[absolute]	91 ms	104.5 ms	-12.96%
❌	test_benchmark_zip_filesystem[simple]	90.3 ms	103.4 ms	-12.62%
❌	test_benchmark_zip_filesystem[virtual-dir]	90.4 ms	103.4 ms	-12.55%
⚡	test_benchmark[_data/loaders/uac/uac-2e44ea6da71d-linux-20250717143106.zip-ZipLoader]	17.8 ms	14.4 ms	+24.06%

Tip

Investigate this regression by commenting @codspeedbot fix this regression on this PR, or directly use the CodSpeed MCP with your agent.

---

_{Comparing refactor-zipfs (f034d34) with main (6e4e1fc)}

[codecov]

Codecov Report

❌ Patch coverage is 97.26027% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 81.30%. Comparing base (6e4e1fc) to head (f034d34).
⚠️ Report is 24 commits behind head on main.

Files with missing lines	Patch %	Lines
dissect/target/filesystems/zip.py	97.10%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1777      +/-   ##
==========================================
+ Coverage   81.20%   81.30%   +0.10%     
==========================================
  Files         405      405              
  Lines       35879    35900      +21     
==========================================
+ Hits        29134    29190      +56     
+ Misses       6745     6710      -35     

Flag	Coverage Δ
unittests	81.30% <97.26%> (+0.10%)	⬆️

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