role childs service add to BaseViewSet

apps/authorization/services/role_child.py

@@ -0,0 +1,15 @@
+import typing
+
+from apps.authorization.models import Role
+
+
+def get_all_role_child(role: Role = None) -> typing.Any:
+    """
+    get all child of an role
+    """
+    descendants = []
+    children = role.child.all()
+    for child in children:
+        descendants.append(child)
+        descendants.extend(get_all_org_child(child))
+    return descendants