Admin: need a way to check for incomplete uploads and manage them

Refer to [discussion 28](https://github.com/orgs/CulverLab/discussions/28) for background information.

There is still a need to check for incomplete uploads (abandoned uploads). A user may have thought they uploaded all the images, but they haven't in reality and they never go back to the upload. They may also intentionally abandon an upload (wrong SD card, for example) and need the upload removed.

What the administrator does with the incomplete upload is up to them, but there will need to be a way to "delete" the upload (make them un-observable to the apps).

There are S3 alternative apps that can be used to delete the uploads, but having detection and potential "removal" in one spot is more efficient.

Start with discussion 28 for the background, then inspect the repository to locate the administration and upload entry points; the issue names no files or tests. Done means an administrator can identify incomplete or abandoned uploads and make selected uploads un-observable to apps from one place.

Written by the indexing model from the issue text.