TF-1973 Fix selection mode still displayed when dragging or moving email

Signed-off-by: dab246 <tdvu@linagora.com>
(cherry picked from commit b02fc22a1c7761bc08b6668d97c36487f05f9874)

model/lib/email/presentation_email.dart

@@ -114,6 +114,8 @@ class PresentationEmail with EquatableMixin {
 
   bool get withAttachments => hasAttachment == true;
 
+  bool get isSelected => selectMode == SelectMode.ACTIVE;
+
   String get routeWebAsString => routeWeb.toString();
 
   bool get pushNotificationActivated => !isDraft && !hasRead;