Raise errors with expected format

[bjester]

Summary

• Updates get_remote_users_info to raise errors with expected format to avoid 500 errors

References

#11540 - does not entirely fix, as there is no error handling (?)

Prior error

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/kolibri/dist/rest_framework/views.py", line 492, in dispatch
    response = handler(request, *args, **kwargs)
  File "/usr/lib/python3/dist-packages/kolibri/core/tasks/api.py", line 198, in create
    validated_data = self.validate_create_req_data(request)
  File "/usr/lib/python3/dist-packages/kolibri/core/tasks/api.py", line 68, in validate_create_req_data
    job, enqueue_args = registered_task.validate_job_data(
  File "/usr/lib/python3/dist-packages/kolibri/core/tasks/registry.py", line 272, in validate_job_data
    validator.is_valid(raise_exception=True)
  File "/usr/lib/python3/dist-packages/kolibri/dist/rest_framework/serializers.py", line 236, in is_valid
    self._validated_data = self.run_validation(self.initial_data)
  File "/usr/lib/python3/dist-packages/kolibri/core/tasks/validation.py", line 123, in run_validation
    value = self.validate(value)
  File "/usr/lib/python3/dist-packages/kolibri/core/auth/tasks.py", line 535, in validate
    facility_info = get_remote_users_info(baseurl, facility_id, username, password)
  File "/usr/lib/python3/dist-packages/kolibri/core/auth/utils/users.py", line 57, in get_remote_users_info
    raise AuthenticationFailed(detail)
rest_framework.exceptions.AuthenticationFailed: [{'id': ErrorDetail(string='AUTHENTICATION_FAILED', code='authentication_failed'), 'message': ErrorDetail(string='401 Client Error: Unauthorized for url: http://192.168.100.49:8080/api/public/facilityuser/?facility_id=13785e243c00fb2b8b0a70b0f2ce0ffe', code='authentication_failed')}]

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/kolibri/dist/django/core/handlers/exception.py", line 41, in inner
    response = get_response(request)
  File "/usr/lib/python3/dist-packages/kolibri/dist/django/core/handlers/base.py", line 187, in _get_response
    response = self.process_exception_by_middleware(e, request)
  File "/usr/lib/python3/dist-packages/kolibri/dist/django/core/handlers/base.py", line 185, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/usr/lib/python3/dist-packages/kolibri/dist/django/views/decorators/csrf.py", line 58, in wrapped_view
    return view_func(*args, **kwargs)
  File "/usr/lib/python3/dist-packages/kolibri/dist/rest_framework/viewsets.py", line 116, in view
    return self.dispatch(request, *args, **kwargs)
  File "/usr/lib/python3/dist-packages/kolibri/dist/rest_framework/views.py", line 495, in dispatch
    response = self.handle_exception(exc)
  File "/usr/lib/python3/dist-packages/kolibri/dist/rest_framework/views.py", line 452, in handle_exception
    response = exception_handler(exc, context)
  File "/usr/lib/python3/dist-packages/kolibri/core/utils/exception_handler.py", line 21, in custom_exception_handler
    response.data = _handle_403_format(response, context)
  File "/usr/lib/python3/dist-packages/kolibri/core/utils/exception_handler.py", line 60, in _handle_403_format
    "id": response.data["detail"].code.upper(),
TypeError: list indices must be integers or slices, not str

Reviewer guidance

Provide incorrect credentials when attempting to import a single learner in the setup wizard

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Testing checklist

• Contributor has fully tested the PR manually
• If there are any front-end changes, before/after screenshots are included
• Critical user journeys are covered by Gherkin stories
• Critical and brittle code paths are covered by unit tests

PR process

• PR has the correct target branch and milestone
• PR has 'needs review' or 'work-in-progress' label
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• If this is an important user-facing change, PR or related issue has a 'changelog' label
• If this includes an internal dependency change, a link to the diff is provided

Reviewer checklist

• Automated test coverage is satisfactory
• PR is fully functional
• PR has been tested for accessibility regressions
• External dependency files were updated if necessary (yarn and pip)
• Documentation is updated
• Contributor is in AUTHORS.md

[rtibbles]

Would be nice if we could lint for this kind of thing - but I've never got my head around how to make custom Python linting rules.

[github-actions]

Build Artifacts

Asset type	Download link
PEX file	kolibri-0.16.0b8.dev0_git.39.gea887029.pex
Windows Installer (EXE)	kolibri-0.16.0b8.dev0+git.39.gea887029-unsigned.exe
Debian Package	kolibri_0.16.0b8.dev0+git.39.gea887029-0ubuntu1_all.deb
Mac Installer (DMG)	kolibri-0.16.0b8.dev0+git.39.gea887029-0.3.0.dmg
Android Package (APK)	kolibri-0.16.0b8.dev0+git.39.gea887029-0.1.0-debug.apk
TAR file	kolibri-0.16.0b8.dev0+git.39.gea887029.tar.gz
WHL file	kolibri-0.16.0b8.dev0+git.39.gea887029-py2.py3-none-any.whl