fix(json): Bound numeric token parsing

[jpnurmi]

Parse numbers from a terminated copy of the token so length-delimited JSON buffers are never read past their declared boundary.

Close: NATIVE-223

[linear-code]

NATIVE-223

[cursor]

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[codecov]

Codecov Report

❌ Patch coverage is 92.30769% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 74.32%. Comparing base (9a275bd) to head (995ebcf).
⚠️ Report is 4 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2067      +/-   ##
==========================================
- Coverage   74.35%   74.32%   -0.04%     
==========================================
  Files         103      103              
  Lines       26677    26730      +53     
  Branches     4855     4868      +13     
==========================================
+ Hits        19836    19866      +30     
- Misses       5503     5519      +16     
- Partials     1338     1345       +7     

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