✨ Correctly parse look{ahead,behind} in regexes

[dubzzz]

Not yet supported at generate time, we at least can flag them as not supported.

Category:

• ✨ Introduce new features
• 📝 Add or update documentation
• ✅ Add or update tests
• 🐛 Fix a bug
• 🏷️ Add or update types
• ⚡️ Improve performance
• Other(s): ...

Potential impacts:

• Generated values
• Shrink values
• Performance
• Typings
• Other(s): ...

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[codecov]

Codecov Report

Merging #3930 (f45015c) into main (61771fe) will decrease coverage by 0.01%.
The diff coverage is 94.11%.

@@            Coverage Diff             @@
##             main    #3930      +/-   ##
==========================================
- Coverage   94.79%   94.78%   -0.01%     
==========================================
  Files         208      208              
  Lines        5701     5716      +15     
  Branches     1283     1290       +7     
==========================================
+ Hits         5404     5418      +14     
- Misses        280      281       +1     
  Partials       17       17              

Flag	Coverage Δ
unit-tests	94.78% <94.11%> (-0.01%)	⬇️
unit-tests-14.x-Linux	94.78% <94.11%> (-0.01%)	⬇️
unit-tests-16.x-Linux	?
unit-tests-18.x-Linux	?
unit-tests-latest-Linux	?

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...ackages/fast-check/src/arbitrary/stringMatching.ts	78.88% <66.66%> (-0.66%)	⬇️
...heck/src/arbitrary/_internals/helpers/ReadRegex.ts	90.47% <100.00%> (+0.39%)	⬆️
.../src/arbitrary/_internals/helpers/TokenizeRegex.ts	94.56% <100.00%> (+0.24%)	⬆️