TF-1328 Add role archive to presentationMailbox

(cherry picked from commit 80ac65d013ec89738606768458c28c56d2fdba10)

model/lib/extensions/presentation_mailbox_extension.dart

@@ -43,6 +43,8 @@ extension PresentationMailboxExtension on PresentationMailbox {
 
   bool get isOutbox => name?.name == PresentationMailbox.outboxRole || role == PresentationMailbox.roleOutbox;
 
+  bool get isArchive => role == PresentationMailbox.roleArchive;
+
   bool get isSubscribedMailbox => isSubscribed != null && isSubscribed?.value == true;
 
   bool get allowedToDisplayCountOfUnreadEmails => !(isTrash || isSpam || isDrafts || isTemplates || isSent) && countUnreadEmails > 0;

model/lib/mailbox/presentation_mailbox.dart

@@ -26,6 +26,7 @@ class PresentationMailbox with EquatableMixin {
   static final roleOutbox = Role(outboxRole);
   static final roleDrafts = Role(draftsRole);
   static final roleSpam = Role(spamRole);
+  static final roleArchive = Role(archiveRole);
 
   final MailboxId id;
   final MailboxName? name;