feat: added wecom notify when printing_job production was completed(new status) and shipment was created

shipment/signals.py

@@ -0,0 +1,11 @@
+"""
+Shipment domain signals.
+"""
+
+from django.dispatch import Signal
+
+# Fired when a Shipment is created via business service.
+# Payload:
+# - instance: Shipment
+# - created_by: Django User (may be None)
+shipment_created = Signal()