TF-3410 Fix wrong text style email subject in EmailView

Signed-off-by: dab246 <tdvu@linagora.com>

lib/features/email/presentation/styles/email_subject_styles.dart

@@ -4,13 +4,9 @@ import 'package:core/utils/platform_info.dart';
 import 'package:flutter/material.dart';
 
 class EmailSubjectStyles {
-  static const double textSize = 20;
   static int? maxLines = PlatformInfo.isWeb ? 2 : null;
 
-  static const Color textColor = AppColor.colorNameEmail;
   static const Color cursorColor = AppColor.colorTextButton;
 
-  static const FontWeight fontWeight = FontWeight.w500;
-
   static const EdgeInsetsGeometry padding = EdgeInsets.symmetric(vertical: 12, horizontal: 16);
 }

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

@@ -1,3 +1,4 @@
+import 'package:core/presentation/utils/theme_utils.dart';
 import 'package:flutter/material.dart';
 import 'package:model/email/presentation_email.dart';
 import 'package:tmail_ui_user/features/email/presentation/styles/email_subject_styles.dart';
@@ -19,11 +20,7 @@ class EmailSubjectWidget extends StatelessWidget {
       child: Text(
         presentationEmail.getEmailTitle(),
         maxLines: EmailSubjectStyles.maxLines,
-        style: const TextStyle(
-          fontSize: EmailSubjectStyles.textSize,
-          color: EmailSubjectStyles.textColor,
-          fontWeight: EmailSubjectStyles.fontWeight
-        )
+        style: ThemeUtils.textStyleHeadingH5(color: Colors.black)
       )
     );
   }