Add dict and json output to dumpstruct

[Schamper]

Refactors dumpstruct to add the ability to generate dict and JSON information about a structure. The rendering is also updated to use this dictionary representation.

Also some small maintenance cleanup on the example scripts.

[codecov]

Codecov Report

❌ Patch coverage is 0% with 170 lines in your changes missing coverage. Please review.
✅ Project coverage is 0.00%. Comparing base (29652dd) to head (79dbeb3).

Files with missing lines	Patch %	Lines
dissect/cstruct/utils.py	0.00%	170 Missing ⚠️

Additional details and impacted files

@@          Coverage Diff           @@
##            main    #156    +/-   ##
======================================
  Coverage   0.00%   0.00%            
======================================
  Files         21      21            
  Lines       2470    2596   +126     
======================================
- Misses      2470    2596   +126     

Flag	Coverage Δ
unittests	0.00% <0.00%> (ø)

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[codspeed-hq]

Merging this PR will not alter performance

✅ 12 untouched benchmarks

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_{Comparing dumpstruct-json (79dbeb3) with main (29652dd)}