✨(domains) get domain expected config for DNS

Call dimail to get DNS configuration values
to make an external domain work and save it in our db.
Add values to serializer for displaying.

src/backend/mailbox_manager/api/client/serializers.py

@@ -74,6 +74,7 @@ class MailDomainSerializer(serializers.ModelSerializer):
             "support_email",
             "last_check_details",
             "action_required_details",
+            "expected_config",
         ]
         read_only_fields = [
             "id",
@@ -85,6 +86,7 @@ class MailDomainSerializer(serializers.ModelSerializer):
             "count_mailboxes",
             "last_check_details",
             "action_required_details",
+            "expected_config",
         ]
 
     def get_action_required_details(self, domain) -> dict:
@@ -122,6 +124,7 @@ class MailDomainSerializer(serializers.ModelSerializer):
         # check domain status and update it
         try:
             client.fetch_domain_status(domain)
+            client.fetch_domain_expected_config(domain)
         except HTTPError as e:
             logger.exception(
                 "[DIMAIL] domain status fetch after creation failed %s with error %s",