enhance: [2.4] Add in-memory cache for casbin enforcer result

[congqixia]

Cherry-pick from master
pr: #35271
See also #35270

[sre-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: congqixia

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• internal/datacoord/OWNERS [congqixia]
• internal/proxy/OWNERS [congqixia]

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[codecov]

Codecov Report

Attention: Patch coverage is 74.28571% with 9 lines in your changes missing coverage. Please review.

Project coverage is 81.13%. Comparing base (1b304e9) to head (c28c5d5).
Report is 6 commits behind head on 2.4.

Files	Patch %	Lines
internal/proxy/privilege_cache.go	70.00%	8 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##              2.4   #35272      +/-   ##
==========================================
- Coverage   81.19%   81.13%   -0.06%     
==========================================
  Files        1047     1053       +6     
  Lines      137322   137022     -300     
==========================================
- Hits       111496   111174     -322     
- Misses      21611    21629      +18     
- Partials     4215     4219       +4     

Files	Coverage Δ
internal/proxy/meta_cache.go	93.37% <100.00%> (+<0.01%)	⬆️
internal/proxy/privilege_interceptor.go	76.57% <100.00%> (+0.87%)	⬆️
internal/proxy/privilege_cache.go	70.00% <70.00%> (ø)

... and 233 files with indirect coverage changes

[SimFG]

/lgtm