🐛(backend) fix dimail call despite mailbox creation failure on our side

When we try to create a duplicate email, a request
to dimail is sent despite a reject on our side.
To solve this issue, we call mailbox creation first
to benefit from validation of our Django model.

Mailbox creation try was called too late after dimail call.
So in attempt to create a duplicated email a request
to dimail was sent despite a failure in our side.

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

@@ -35,8 +35,7 @@ class MailboxSerializer(serializers.ModelSerializer):
         """
         Override create function to fire a request on mailbox creation.
         """
-        mailbox_status = enums.MailDomainStatusChoices.PENDING
-
+        mailbox = super().create(validated_data)
         if validated_data["domain"].status == enums.MailDomainStatusChoices.ENABLED:
             client = DimailAPIClient()
             # send new mailbox request to dimail
@@ -48,8 +47,8 @@ class MailboxSerializer(serializers.ModelSerializer):
             mailbox_data = json.loads(
                 response.content.decode("utf-8").replace("'", '"')
             )
-
-            mailbox_status = enums.MailDomainStatusChoices.ENABLED
+            mailbox.status = enums.MailDomainStatusChoices.ENABLED
+            mailbox.save()
 
             # send confirmation email
             client.notify_mailbox_creation(
@@ -57,7 +56,7 @@ class MailboxSerializer(serializers.ModelSerializer):
             )
 
         # actually save mailbox on our database
-        return models.Mailbox.objects.create(**validated_data, status=mailbox_status)
+        return mailbox
 
 
 class MailDomainSerializer(serializers.ModelSerializer):