Student profile CSV background task tech debt

TNL-525

These 4 commits address 4 fairly small instances of technical debt that @nasthagiri and I came across while working on the backgroundify student profile CSV story.

@jimabramson @nasthagiri please review.

@cahrens FYI
I wanted to keep a 1:1 `update_task_progress`:`task_progress.update_task_state()` relationship, as this story felt like more of a refactor than a code improvement task.