TF-1718 Check List-Unsubscribe in header of email & parsing to EmailUnsubscribe

(cherry picked from commit 9dc046a951e5198461178860c8ebe4bedff9062f)

model/lib/extensions/email_extension.dart

@@ -1,6 +1,8 @@
 
 import 'dart:convert';
 
+import 'package:collection/collection.dart';
+import 'package:core/utils/app_logger.dart';
 import 'package:jmap_dart_client/jmap/core/properties/properties.dart';
 import 'package:jmap_dart_client/jmap/mail/email/email.dart';
 import 'package:jmap_dart_client/jmap/mail/email/email_body_part.dart';
@@ -11,6 +13,8 @@ import 'package:model/model.dart';
 
 extension EmailExtension on Email {
 
+  static const String unsubscribeHeaderName = 'List-Unsubscribe';
+
   String asString() => jsonEncode(toJson());
 
   bool get hasRead => keywords?.containsKey(KeyWordIdentifier.emailSeen) == true;
@@ -23,6 +27,14 @@ extension EmailExtension on Email {
 
   bool get withAttachments => hasAttachment == true;
 
+  String get listUnsubscribe {
+    final listUnsubscribe = headers?.firstWhereOrNull((header) => header.name == unsubscribeHeaderName);
+    log('EmailExtension::listUnsubscribe: $listUnsubscribe');
+    return listUnsubscribe?.value ?? '';
+  }
+
+  bool get hasListUnsubscribe => listUnsubscribe.isNotEmpty;
+
   bool hasReadReceipt(Map<MailboxId, PresentationMailbox> mapMailbox) {
     final mailboxCurrent = findMailboxContain(mapMailbox);
     return !hasMdnSent &&