refactor policy config structs

[pdabelf5]

Proposed changes

Small refactor to put all related policy configuration into one structure:

• RateLimit
• JWTAuth
• APIKey

Checklist

Before creating a PR, run through this checklist and mark each as complete.

• I have read the CONTRIBUTING doc
• I have added tests that prove my fix is effective or that my feature works
• I have checked that all unit tests pass after adding my changes
• I have updated necessary documentation
• I have rebased my branch onto main
• I will ensure my PR is targeting the main branch and pulling from my branch from my own fork

[codecov]

Codecov Report

Attention: Patch coverage is 76.81159% with 16 lines in your changes missing coverage. Please review.

Project coverage is 52.70%. Comparing base (bce0a1c) to head (7914235).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
internal/configs/virtualserver.go	76.81%	13 Missing and 3 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #7232      +/-   ##
==========================================
- Coverage   52.72%   52.70%   -0.02%     
==========================================
  Files          89       89              
  Lines       20843    20843              
==========================================
- Hits        10989    10985       -4     
- Misses       9396     9398       +2     
- Partials      458      460       +2     

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