Add custom fields to `result` field of `TaskResult` on Failure.

[oahshtsua]

I'm using Django with Celery and django-celery-results. When a task fails, django-celery-results seems to store information about the exception that caused the failure. I would like to enhance the result field of the TaskResult model when a task fails by adding custom keys alongside the default exception details which I need to include for additional bookkeeping data. How would I go about doing this?

Current Result:

{
  "exc_type": "ValueError",
  "exc_message": ["this is a custom raised exception...."],
  "exc_module": "builtins"
}

Expected Result:

{
  "exc_type": "ValueError",
  "exc_message": ["this is a custom raised exception...."],
  "exc_module": "builtins",
  "custom_field_1": "value_1",
  "custom_field_2": "value_2"
}

Environment:

django==4.2.11
celery==5.4.0
django-celery-results==2.5.1