fix for duplicate cidr local rate limit rules

[erik-hunter]

What type of PR is this?
Fix for duplicated rate limit rules.

What this PR does / why we need it:
Allow multiple local rate limit rules with CIDR matchers. Follows same pattern used for other ratelimit rules by adding index into the descriptor.

Which issue(s) this PR fixes:

Fixes #8632

[netlify]

✅ Deploy Preview for cerulean-figolla-1f9435 canceled.

Name	Link
🔨 Latest commit	3d8c0a4
🔍 Latest deploy log	https://app.netlify.com/projects/cerulean-figolla-1f9435/deploys/69cde09efbc7e9000812d88f

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 74.38%. Comparing base (ac18feb) to head (3d8c0a4).
⚠️ Report is 3 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #8650      +/-   ##
==========================================
- Coverage   74.38%   74.38%   -0.01%     
==========================================
  Files         243      243              
  Lines       38350    38356       +6     
==========================================
+ Hits        28528    28530       +2     
- Misses       7822     7827       +5     
+ Partials     2000     1999       -1     

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[zirain]

@jukie need to backport?