feat: upgrading simple api to drf compatible.

lms/djangoapps/instructor/views/serializer.py

@@ -4,18 +4,7 @@
 from django.core.exceptions import ValidationError
 from django.utils.translation import gettext as _
 from rest_framework import serializers
-from .tools import (
-    dump_block_extensions,
-    dump_student_extensions,
-    find_unit,
-    get_student_from_identifier,
-    handle_dashboard_error,
-    keep_field_private,
-    parse_datetime,
-    require_student_from_identifier,
-    set_due_date_extension,
-    strip_if_string,
-)
+from .tools import get_student_from_identifier
 from common.djangoapps.util.json_request import JsonResponse
 
 from lms.djangoapps.instructor.access import ROLES