[RLQS] Support per route/vhost config

*Description*:
The doc is a bit confusing since it says this is [supported]( https://www.envoyproxy.io/docs/envoy/latest/configuration/http/http_filters/rate_limit_quota_filter#rate-limit-quota-override). Is per-route/vhost override for this filter on a roadmap or in progress anywhere? Didn't find an existing issue/PR for it.

Start with the Rate Limit Quota Filter documentation section linked in the issue, especially “rate-limit-quota-override,” and compare its wording with the requested per-route/vhost behavior. Done requires a maintainer-confirmed roadmap or scope and a concrete implementation plan; the issue names no source files or tests.

Written by the indexing model from the issue text.