test: fuzz testing with cargo-fuzz

[ferbetanzo]

This is not intended to be merged as it includes some changes to hugr-model and the devenv.

Please check the README.md for how to run the fuzzing targets.

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 14 lines in your changes missing coverage. Please review.

Project coverage is 82.01%. Comparing base (56906ce) to head (b5e68ff).

Files with missing lines	Patch %	Lines
hugr-model/src/v0/ast/mod.rs	0.00%	9 Missing ⚠️
hugr-model/src/v0/mod.rs	0.00%	5 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2316      +/-   ##
==========================================
- Coverage   82.03%   82.01%   -0.03%     
==========================================
  Files         245      245              
  Lines       45216    45230      +14     
  Branches    40960    40974      +14     
==========================================
  Hits        37095    37095              
- Misses       6108     6122      +14     
  Partials     2013     2013              

Flag	Coverage Δ
python	85.36% <ø> (ø)
rust	81.66% <0.00%> (-0.03%)	⬇️

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