Add detailed_metric support for xds-config

[akondapuram]

[Please NOTE] This PR has to be merged only after receiving approval for the PR on the go-control-plane.

1. This PR adds support for detailed_metric field to dynamic ratelimiting in response to the issue I created a few weeks ago.
2. The reason service RateLimitConfigDiscoveryService has been removed from this particular rls_conf.proto is because protoc would not compile it correctly. I think this was added after this file (rls_conf.pb.go) was generated and checked-in to go-control-plane repo.
3. Please see commit for when rls_conf_ds.proto was initially added, but it was later removed as part of another commit.
4. In the final commit rls_conf.proto was added along with service, but the corresponding go-control-plane's files were not updated. Hence, removing it to reduce confusion here. (Another possible solution is to separate it out to another file (rls_conf_ds.proto) like before.

[dmi3zkm]

Hey @envoyproxy/ratelimit-maintainers
Could you please review this PR?

[birdayz]

bump :)
it would be really nice if we could merge this. the API part is merged into envoy's go-control-plane already.

[akondapuram]

@birdayz Though the PR is merged, currently awaiting the release of the new version of the go-control-plane repo. The latest version is from 4 weeks ago and doesn't have my changes yet. https://pkg.go.dev/github.com/envoyproxy/go-control-plane/ratelimit/config/ratelimit/v3

[birdayz]

Thanks for the quick response.
We could also depend on the commit 841e293a220b4d5abcc84ec0df41fd10a259ae42 directly (instead of using the tag), until the release of go-control-plane has happened. But i don't know if that is against some policy of the ratelimit project.

[akondapuram]

@birdayz Thank you for the suggestion. I used commit instead of tag now and converted this PR from draft to review.
@renuka-fernando Could you please review when you get some time? Thank you in advance.

[renuka-fernando]

Other changes LGTM.

[akondapuram]

@renuka-fernando Thank you for your review and approval.

[akondapuram]

@envoyproxy/ratelimit-maintainers Could you please help merge this PR? Thank you.

[ramaraochavali]

@mattklein123 @ysawa0 Can you please help merge this?

changed mind

[mattklein123]

Please check CI.

Also, is this a breaking change? It's a little unclear to me.

[akondapuram]

@mattklein123 Thank you for looking into this. It's not a breaking change, but this has dependency on the go-control-plane repo as we rely on rls_conf.pb.go file. This was merged a couple of weeks ago. Hence I kept this PR in draft until that was merged. Converted it to review after the other PR was merged.

Regarding the CI, Looks like there was a pre-commit end-of-file failure for rls_conf_ds.proto. Pushed a new commit. Could you please try to re-run the checks when you have some bandwidth? Thank you.

[akondapuram]

@mattklein123 Looks like all the checks are successful, could you please help merge this when you get some time? Thank you.

[akondapuram]

@mattklein123 Thank you for your review and approval.