EE: PLT-4512 Show secret in addition to QR code when activating MFA (#4427)

* EE: Update MFA to display secret for manual entry

* Width adjustments for secret (#4423)

* Add unit test

webapp/client/client.jsx

@@ -990,6 +990,15 @@ export default class Client {
         this.track('api', 'api_users_oauth_to_email');
     }
 
+    generateMfaSecret(success, error) {
+        request.
+            get(`${this.getUsersRoute()}/generate_mfa_secret`).
+            set(this.defaultHeaders).
+            type('application/json').
+            accept('application/json').
+            end(this.handleResponse.bind(this, 'generateMfaSecret', success, error));
+    }
+
     revokeSession(altId, success, error) {
         request.
             post(`${this.getUsersRoute()}/revoke_session`).