Implement query_exactly_one

[divarvel]

Continuation of #214 rebased on the latest main

[codspeed-hq]

CodSpeed Performance Report

Merging #260 will not alter performance

_{Comparing query_exactly_one (e58e7bd) with main (f4473ee)}

Summary

✅ 12 untouched benchmarks

[codecov]

Codecov Report

Attention: Patch coverage is 85.71429% with 1 line in your changes missing coverage. Please review.

Project coverage is 67.41%. Comparing base (f4473ee) to head (e58e7bd).

Files with missing lines	Patch %	Lines
biscuit-capi/src/lib.rs	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #260      +/-   ##
==========================================
+ Coverage   67.39%   67.41%   +0.01%     
==========================================
  Files          39       39              
  Lines        7235     7242       +7     
==========================================
+ Hits         4876     4882       +6     
- Misses       2359     2360       +1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.