message: Add cache to `user-profile-follower-badge`
diff: import './user-profile-follower-badge.css';
  import React from 'dom-chef';
  +import cache from 'webext-storage-cache';
  import select from 'select-dom';
  import * as api from '../libs/api';
  import features from '../libs/features';
  import {getUsername, getCleanPathname} from '../libs/utils';
  -async function init(): Promise<void> {
  - const {httpStatus} = await api.v3(
  - `users/${getCleanPathname()}/following/${getUsername()}`,
  - {ignoreHTTPStatus: true}
  - );
  +const doesUserFollow = cache.function(async (userA: string, userB: string): Promise<boolean> => {
  + const {httpStatus} = await api.v3(`users/${userA}/following/${userB}`, {
  + ignoreHTTPStatus: true
  + });
  - if (httpStatus === 204) {
  + return httpStatus === 204;
  +}, {
  + maxAge: 3,
  + cacheKey: ([userA, userB]) => `user-follows:${userA}:${userB}`
  +});
  +
  +async function init(): Promise<void> {
  + if (await doesUserFollow(getCleanPathname(), getUsername())) {
  select('.vcard-names-container:not(.is-placeholder)')!.after(
  <div className="rgh-follower-badge">Follows you</div>
  );
  