Enable re-download images feature

[rstorey]

User story/persona
As a community manager, I want to use the re-download images feature so that I can replace corrupted images that were already published in a campaign.

Additional context
Because of the @update_task_status decorator, we need to create a data model to back the redownload images feature jobs. The only other way to use the feature is to rebuild the application without the decorator - in which case, import job status won't be saved in the database.

Acceptance Criteria

• Be able to use the importer with saved status in the database for import item asset jobs
• Be able to use the redownload images feature with saved status in the database for asynchronous jobs

[lalgee]

Community managers can now replace individual asset images using #1575
or replace in bulk via AWS