[CLIENT-3106] Convert POLICY_SET_FIELD() macro into an inline function

[juliannguyen4]

Makes POLICY_SET_FIELD() more readable, easier to debug, and it should have the same performance as a macro.

Extra changes:

• Enable -Winline flag so we know if the compiler is actually making a function inline or not

TODO

• Verify performance using perf regression tests
• Add -Winline and -Werror flag to build-wheels.yml

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 80.00000% with 4 lines in your changes missing coverage. Please review.

Project coverage is 82.00%. Comparing base (cd0e783) to head (402f955).
Report is 2 commits behind head on dev.

Files with missing lines	Patch %	Lines
src/main/policy.c	80.00%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##              dev     #802      +/-   ##
==========================================
- Coverage   82.00%   82.00%   -0.01%     
==========================================
  Files          99       99              
  Lines       14698    14718      +20     
==========================================
+ Hits        12053    12069      +16     
- Misses       2645     2649       +4     

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