feat(authenticator): TOTP MFA (#3609)

Adds TOTP MFA feature to The Authenticator package.

CONTRIBUTING.md

@@ -20,6 +20,7 @@ Thank you for your interest in contributing to our project! <3 Whether it's a bu
   - [Unit Tests](#unit-tests)
   - [Integration Tests](#integration-tests)
   - [Provision Resources For Integration Tests](#provision-resources-for-integration-tests)
+  - [Screenshot Tests](#screenshot-tests)
   - [Code of Conduct](#code-of-conduct)
   - [Security issue notifications](#security-issue-notifications)
   - [Licensing](#licensing)
@@ -248,6 +249,17 @@ $ tool/provision_integration_test_resources.sh
 
 This script can be re-run anytime the environments need to be updated. Further information can be found in the [infra](infra/README.md) package.
 
+## Screenshot Tests
+
+The Amplify Authenticator package contains a screenshot test suite called `goldens`. If your changes include UI changes within this package please regenerate the goldens.
+
+To regenerate, navigate to the root of the Authenticator package and run:
+
+```bash
+$ cd packages/authenticator/amplify_authenticator
+$ flutter test --update-goldens
+```
+
 ## Code of Conduct
 
 This project has adopted the [Amazon Open Source Code of Conduct](https://aws.github.io/code-of-conduct).

packages/auth/amplify_auth_cognito/example/integration_test/mfa_sms_totp_optional_test.dart

@@ -8,7 +8,6 @@ import 'package:checks/checks.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 import 'test_runner.dart';
-import 'utils/totp_utils.dart';
 
 void main() {
   testRunner.setupTests();

packages/auth/amplify_auth_cognito/example/integration_test/mfa_sms_totp_required_test.dart

@@ -9,7 +9,6 @@ import 'package:checks/checks.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 import 'test_runner.dart';
-import 'utils/totp_utils.dart';
 
 void main() {
   testRunner.setupTests();

packages/auth/amplify_auth_cognito/example/integration_test/mfa_totp_optional_test.dart

@@ -8,7 +8,6 @@ import 'package:checks/checks.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 import 'test_runner.dart';
-import 'utils/totp_utils.dart';
 
 void main() {
   testRunner.setupTests();

packages/auth/amplify_auth_cognito/example/integration_test/mfa_totp_required_test.dart

@@ -9,7 +9,6 @@ import 'package:checks/checks.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 import 'test_runner.dart';
-import 'utils/totp_utils.dart';
 
 void main() {
   testRunner.setupTests();

packages/authenticator/amplify_authenticator/example/integration_test/main_test.dart

@@ -13,7 +13,9 @@ import 'http_test.dart' as http_tests;
 import 'reset_password_test.dart' as reset_password_tests;
 import 'sign_in_force_new_password_test.dart'
     as sign_in_force_new_password_tests;
-import 'sign_in_mfa_test.dart' as sign_in_mfa_tests;
+import 'sign_in_mfa_sms_test.dart' as sign_in_mfa_sms_tests;
+import 'sign_in_mfa_sms_totp_test.dart' as sign_in_mfa_sms_totp_tests;
+import 'sign_in_mfa_totp_test.dart' as sign_in_mfa_totp_tests;
 import 'sign_in_with_email_test.dart' as sign_in_with_email_tests;
 import 'sign_in_with_phone_test.dart' as sign_in_with_phone_tests;
 import 'sign_in_with_username_test.dart' as sign_in_with_username_tests;
@@ -37,7 +39,9 @@ void main() {
     http_tests.main();
     reset_password_tests.main();
     sign_in_force_new_password_tests.main();
-    sign_in_mfa_tests.main();
+    sign_in_mfa_sms_tests.main();
+    sign_in_mfa_sms_totp_tests.main();
+    sign_in_mfa_totp_tests.main();
     sign_in_with_email_tests.main();
     sign_in_with_phone_tests.main();
     sign_in_with_username_tests.main();