TF-3023 Write widget test for SMimeSignatureStatus icon

lib/features/email/presentation/extensions/presentation_email_extension.dart

@@ -2,14 +2,15 @@
 import 'package:model/email/presentation_email.dart';
 import 'package:model/extensions/list_email_header_extension.dart';
 import 'package:tmail_ui_user/features/email/presentation/model/smime_signature_status.dart';
+import 'package:tmail_ui_user/features/email/presentation/utils/smime_signature_constant.dart';
 
 extension PresentationEmailExtension on PresentationEmail {
 
   SMimeSignatureStatus get sMimeStatus {
     final status = emailHeader?.toSet().sMimeStatus;
-    if (status == 'Good signature') {
+    if (status == SMimeSignatureConstant.GOOD_SIGNATURE) {
       return SMimeSignatureStatus.goodSignature;
-    } else  if (status == 'Bad signature') {
+    } else  if (status == SMimeSignatureConstant.BAD_SIGNATURE) {
       return SMimeSignatureStatus.badSignature;
     } else {
       return SMimeSignatureStatus.notSigned;

lib/features/email/presentation/utils/smime_signature_constant.dart

@@ -0,0 +1,5 @@
+
+class SMimeSignatureConstant {
+  static const String GOOD_SIGNATURE = 'Good signature';
+  static const String BAD_SIGNATURE = 'Bad signature';
+}

lib/features/email/presentation/widgets/information_sender_and_receiver_builder.dart

@@ -32,7 +32,7 @@ class InformationSenderAndReceiverBuilder extends StatelessWidget {
     required this.emailSelected,
     required this.responsiveUtils,
     required this.imagePaths,
-    required this.emailUnsubscribe,
+    this.emailUnsubscribe,
     this.maxBodyHeight,
     this.openEmailAddressDetailAction,
     this.onEmailActionClick,
@@ -66,6 +66,7 @@ class InformationSenderAndReceiverBuilder extends StatelessWidget {
                       )),
                       if (emailSelected.sMimeStatus != SMimeSignatureStatus.notSigned)
                         Tooltip(
+                          key: const Key('smime_signature_status_icon'),
                           message: emailSelected.sMimeStatus.getTooltipMessage(context),
                           child: MouseRegion(
                             cursor: SystemMouseCursors.click,