CLDSRV-767: Add counter and cached config storage

[tmacro]

Adds simple in memory storage for GCRA counters and cached bucket limit configurations.

Note for reviewers: This is being merged into a feature branch that has existing skeleton code. All unreviewed code will be gone over/reworked before merging into development/9.0

[Copilot]

Pull Request Overview

This PR introduces in-memory storage mechanisms for rate limiting functionality, including GCRA counters and cached bucket limit configurations. The implementation uses JavaScript Maps to provide simple, ephemeral storage for rate limit tracking.

Key Changes:

• Added cache module with counter storage and cached config storage functionality
• Implemented expiration mechanisms for both counters and cached configurations
• Created comprehensive unit tests covering storage, retrieval, and expiration behaviors

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
lib/api/apiUtils/rateLimit/cache.js	Implements in-memory storage for GCRA counters and limit configurations with expiration logic
tests/unit/api/apiUtils/rateLimit/cache.js	Provides unit test coverage for counter and config cache operations including expiration scenarios

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[codecov]

Codecov Report

❌ Patch coverage is 96.42857% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 82.60%. Comparing base (f44a1ec) to head (ce7fa89).
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
lib/api/apiUtils/rateLimit/cache.js	96.42%	1 Missing ⚠️

Additional details and impacted files

Files with missing lines	Coverage Δ
lib/api/apiUtils/rateLimit/cache.js	96.42% <96.42%> (ø)

@@                               Coverage Diff                               @@
##           improvement/CLDSRV-766/bucket_rate_limiting    #5977      +/-   ##
===============================================================================
+ Coverage                                        82.57%   82.60%   +0.03%     
===============================================================================
  Files                                              194      195       +1     
  Lines                                            12324    12352      +28     
===============================================================================
+ Hits                                             10176    10203      +27     
- Misses                                            2148     2149       +1     

Flag	Coverage Δ
ceph-backend-test	65.18% <0.00%> (-0.14%)	⬇️
file-ft-tests	66.02% <0.00%> (-0.16%)	⬇️
kmip-ft-tests	26.70% <0.00%> (-0.07%)	⬇️
mongo-v0-ft-tests	67.34% <0.00%> (-0.13%)	⬇️
mongo-v1-ft-tests	67.33% <0.00%> (-0.16%)	⬇️
multiple-backend	35.28% <0.00%> (-0.40%)	⬇️
quota-tests	31.90% <0.00%> (-0.05%)	⬇️
quota-tests-inflights	33.81% <0.00%> (-0.07%)	⬇️
unit	66.98% <96.42%> (+0.06%)	⬆️
utapi-v2-tests	32.99% <0.00%> (-0.08%)	⬇️

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