✨(backend) allow to create a new user in a marketing system

We want to create a new user in a marketing system to create a dedicated
onboarding for each of them. The marketing service is implemented in the
django-lasuite library and it is possible to pick the backend we want
or implement a new one following the documentation on this library.

Author: lunika

CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to
 ### Added
 
 - ⚡️(frontend) export html #1669
+- ✨(backend) allow to create a new user in a marketing system
 
 ### Changed