TF-1718 Implement unsubscribeMail on Jmap server

Signed-off-by: dab246 <tdvu@linagora.com>
(cherry picked from commit 0f61a97aab513cda75c65e3c92ebcf8f6290b6ec)

model/lib/email/presentation_email.dart

@@ -13,6 +13,7 @@ import 'package:jmap_dart_client/jmap/mail/email/keyword_identifier.dart';
 import 'package:jmap_dart_client/jmap/mail/mailbox/mailbox.dart';
 import 'package:model/email/email_content.dart';
 import 'package:model/extensions/email_address_extension.dart';
+import 'package:model/extensions/keyword_identifier_extension.dart';
 import 'package:model/extensions/media_type_nullable_extension.dart';
 import 'package:model/mailbox/presentation_mailbox.dart';
 import 'package:model/mailbox/select_mode.dart';
@@ -110,6 +111,8 @@ class PresentationEmail with EquatableMixin {
 
   bool get isForwarded => keywords?.containsKey(KeyWordIdentifier.emailForwarded) == true;
 
+  bool get isSubscribed => keywords?.containsKey(KeyWordIdentifierExtension.unsubscribeMail) == true;
+
   bool get isAnsweredAndForwarded => isAnswered && isForwarded;
 
   bool get withAttachments => hasAttachment == true;

model/lib/extensions/email_extension.dart

@@ -25,6 +25,8 @@ extension EmailExtension on Email {
 
   bool get isDraft => keywords?.containsKey(KeyWordIdentifier.emailDraft) == true;
 
+  bool get isUnsubscribed => keywords?.containsKey(KeyWordIdentifierExtension.unsubscribeMail) == true;
+
   bool get withAttachments => hasAttachment == true;
 
   String get listUnsubscribe {