Used local Blob Service for testing.
For deleteUpload, used the `delete_upload` keyserver endpoint (easy way is canceling media message on web, with blob uploads enabled). Called the endpoint and verified that blob associated with the upload was deleted from DDB.
For deleting unassigned uploads: Manually modified MariaDB by setting containers to null and age to be older than 24h. Modified the cron job call to instead run during keyserver startup. Verified that holders were removed.