enable rate limit for month and year

[rpahli]

What type of PR is this?

adds the option to set rate limit unit to Month and Year which was introduced with envoy 1.25.

What this PR does / why we need it:

Which issue(s) this PR fixes:

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 8 lines in your changes missing coverage. Please review.

Project coverage is 65.74%. Comparing base (544bd9c) to head (d123cb6).
Report is 8 commits behind head on main.

Files with missing lines	Patch %	Lines
internal/gatewayapi/backendtrafficpolicy.go	0.00%	4 Missing ⚠️
internal/xds/translator/local_ratelimit.go	0.00%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4495      +/-   ##
==========================================
- Coverage   65.95%   65.74%   -0.21%     
==========================================
  Files         203      210       +7     
  Lines       31154    31524     +370     
==========================================
+ Hits        20547    20726     +179     
- Misses       9420     9602     +182     
- Partials     1187     1196       +9     

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[arkodg]

thanks for the submitting the PR @rpahli !

you probably need a few more changes

• in ratelimit service https://github.com/envoyproxy/ratelimit/blob/28b1629a21e885bdd2b527d6a1c1de8483dc47d4/src/utils/utilities.go#L19
• https://github.com/envoyproxy/ratelimit/blob/28b1629a21e885bdd2b527d6a1c1de8483dc47d4/api/ratelimit/config/ratelimit/v3/rls_conf.proto#L78

can you also add a test case in https://github.com/envoyproxy/gateway/tree/main/internal/xds/translator/testdata/in/ratelimit-config / https://github.com/envoyproxy/gateway/tree/main/internal/xds/translator/testdata/out/ratelimit-config

and an addition to https://github.com/envoyproxy/gateway/blob/main/test/e2e/tests/ratelimit.go to make sure it works e2e