TF-3449 Set priority headers in email object when send or save draft email

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

lib/features/composer/presentation/model/create_email_request.dart

@@ -19,6 +19,7 @@ class CreateEmailRequest with EquatableMixin {
   final String subject;
   final String emailContent;
   final bool hasRequestReadReceipt;
+  final bool isMarkAsImportant;
   final Set<EmailAddress>? fromSender;
   final Set<EmailAddress>? toRecipients;
   final Set<EmailAddress>? ccRecipients;
@@ -50,6 +51,7 @@ class CreateEmailRequest with EquatableMixin {
     this.bccRecipients,
     this.replyToRecipients,
     this.hasRequestReadReceipt = true,
+    this.isMarkAsImportant = false,
     this.identity,
     this.attachments,
     this.inlineAttachments,
@@ -79,6 +81,7 @@ class CreateEmailRequest with EquatableMixin {
     replyToRecipients,
     identity,
     hasRequestReadReceipt,
+    isMarkAsImportant,
     attachments,
     inlineAttachments,
     outboxMailboxId,

lib/features/composer/presentation/model/mail_priority_header.dart

@@ -0,0 +1,27 @@
+
+import 'package:equatable/equatable.dart';
+
+class MailPriorityHeader with EquatableMixin {
+  final String? xPriority;
+  final String? importance;
+  final String? priority;
+
+  MailPriorityHeader({
+    this.xPriority,
+    this.importance,
+    this.priority,
+  });
+
+  factory MailPriorityHeader.asImportant() => MailPriorityHeader(
+    xPriority: '1',
+    importance: 'high',
+    priority: 'urgent',
+  );
+
+  @override
+  List<Object?> get props => [
+    xPriority,
+    importance,
+    priority,
+  ];
+}