feat(client): ts-migrate WithInstantSearch.js (#42923)

* rename to TS

* update import

* migrate with-instant-search

* change falsy values to empty string

* update import order

Finish resolving conflict from #41824

* update import order for search-bar

* update setTimeout() type

config/read-env.js

@@ -46,11 +46,11 @@ module.exports = Object.assign(locations, {
   environment: process.env.FREECODECAMP_NODE_ENV || 'development',
   algoliaAppId:
     !algoliaAppId || algoliaAppId === 'app_id_from_algolia_dashboard'
-      ? null
+      ? ''
       : algoliaAppId,
   algoliaAPIKey:
     !algoliaAPIKey || algoliaAPIKey === 'api_key_from_algolia_dashboard'
-      ? null
+      ? ''
       : algoliaAPIKey,
   paypalClientId:
     !paypalClientId || paypalClientId === 'id_from_paypal_dashboard'