Add support for Prometheus integration

ui/src/hooks/index.tsx

@@ -1,4 +1,5 @@
-import { useEffect } from "react";
+import { useEffect, useMemo } from "react";
+import { useLocation } from "react-router-dom";
 
 // usePolling repeatedly calls doFn with a fix time delay specified
 // by interval (in millisecond).
@@ -9,3 +10,9 @@ export function usePolling(doFn: () => void, interval: number) {
     return () => clearInterval(id);
   }, [interval, doFn]);
 }
+
+// useQuery gets the URL search params from the current URL.
+export function useQuery(): URLSearchParams {
+  const { search } = useLocation();
+  return useMemo(() => new URLSearchParams(search), [search]);
+}