TabsManager in react (#500)

src/hooks/useObservable.ts

@@ -0,0 +1,13 @@
+import { Observable } from "knockout";
+import { useEffect, useState } from "react";
+
+export function useObservable<T>(observable: Pick<Observable<T>, "subscribe" | "peek">): T {
+  const [, setValue] = useState(0);
+
+  useEffect(() => {
+    const subscription = observable.subscribe(() => setValue((n) => 1 + n), undefined, "change");
+    return () => subscription.dispose();
+  }, [observable]);
+
+  return observable.peek();
+}