Replaced redux with zustand. Fixed login issue, closes #980.

hooks/useUser.js

@@ -0,0 +1,9 @@
+import useStore, { setUser } from 'store/app';
+
+const selector = state => state.user;
+
+export default function useUser() {
+  const user = useStore(selector);
+
+  return { user, setUser };
+}