JZ: Relocate import csv tests & fixtures
JZ: Add celery task wrapper & progress polling fx
JZ: Add csv_import task to celery imports
JZ: CSVimport view to handle async & sync import

Based on csv row count
JZ: Fix style test fail
JZ: Fix async csv imports and polling
JZ: Fix typo chech => check
JZ: Specify csv import task for celery
ME: added test: anonymous users can access shared data when accessing media endpoint
ME: anonymous users should access shared data when accessing media enpoint
ME: changed the super class to 'DjangoModelPermissionsOrAnonReadOnly'
UK: allow authenticated_users_only=False, updated tests
UK: for anon users shared_data=True