[Router] Add bucket-aware policy domains and native cache indexing (#38108)

Signed-off-by: Vincent Gao <vincentbo@linux.alibaba.com>
Co-authored-by: inkcherry <mingzhi.liu@amd.com>
Co-authored-by: yangbodong22011 <13137470+yangbodong22011@users.noreply.github.com>

experimental/sgl-router/tests/component/discovery/static_urls.rs

@@ -130,6 +130,8 @@ async fn static_urls_pd_role_resolved_end_to_end() {
             id: "tiny".into(),
             tokenizer_path: "tests/fixtures/tiny_tokenizer.json".into(),
             policy: sgl_router::config::PolicyKind::RoundRobin,
+            decode_policy: Default::default(),
+            bucket_config: None,
             circuit_breaker: None,
             cache_aware: None,
             sticky: None,