add notification and send notification

core/apps/notifications/models/notification.py

@@ -0,0 +1,9 @@
+from django.db import models
+
+from core.apps.shared.models import BaseModel
+from core.apps.accounts.models import User
+
+class Notification(BaseModel):
+    user = models.ForeignKey(User, on_delete=models.CASCADE, related_name='notifications')
+    token = models.CharField(max_length=255, unique=True)
+