feat(client): add growthbook (#48003)

* feat: initial set up

* feat: useFeature setup

* feat: adjust attributes

* chore(client): remove ts-disables in growth-book-wrapper

* feat: pull growthbook uri from env

* feat: adjust the staff atribute

* feat: make linter happy

* feat: update recruitment message

* refactor: simplify types

* chore: delete unused config

* fix: update copy

* fix: add growthbookUri to expected env vars

Co-authored-by: Shaun Hamilton <shauhami020@gmail.com>
Co-authored-by: Oliver Eyton-Williams <ojeytonwilliams@gmail.com>

tools/scripts/build/ensure-env.ts

@@ -52,12 +52,14 @@ if (FREECODECAMP_NODE_ENV !== 'development') {
   const searchKeys = ['algoliaAppId', 'algoliaAPIKey'];
   const donationKeys = ['stripePublicKey', 'paypalClientId', 'patreonClientId'];
   const loggingKeys = ['sentryClientDSN'];
+  const abTestingKeys = ['growthbookUri'];
 
   const expectedVariables = locationKeys.concat(
     deploymentKeys,
     searchKeys,
     donationKeys,
-    loggingKeys
+    loggingKeys,
+    abTestingKeys
   );
   const actualVariables = Object.keys(env as Record<string, unknown>);
   if (expectedVariables.length !== actualVariables.length) {