Add Cellebrite UFDX and UFD loader

[JSCU-CNI]

This PR adds support for Cellebrite's UFDX and UFD full filesystem (FFS) exports. This has only been tested on Digital Corpora's iOS 17 image. This PR loosely relates to #1085 as the image OS is recognized correctly with that branch.

[Schamper]

Only some small things. I like the small custom filesystem subclass, usually I would've just inlined that logic in the map method itself, but this has its benefits.

[codecov]

Codecov Report

Attention: Patch coverage is 91.73554% with 10 lines in your changes missing coverage. Please review.

Project coverage is 79.15%. Comparing base (adda634) to head (22fb9fa).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
dissect/target/loaders/cellebrite.py	89.79%	10 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1086      +/-   ##
==========================================
+ Coverage   79.10%   79.15%   +0.04%     
==========================================
  Files         341      342       +1     
  Lines       30181    30281     +100     
==========================================
+ Hits        23875    23968      +93     
- Misses       6306     6313       +7     

Flag	Coverage Δ
unittests	79.15% <91.73%> (+0.04%)	⬆️

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