Uploader: Current Uploading workflow is complex for people unfamiliar/forgetting with the process

After talking to Liz (Java app trainer), there are users that don't remember how to upload images from one session to the next (with a time gap in between sessions). Simplify the interface for uploads while preserving features.

Suggested changes per step: Hide most of the controls and add text to assist:
- Files: Expand the "Drop a folder of media" to say something along the lines of "Drop folder to upload or click Choose Folder to browse"
- Inspect: hide details of files behind a drop-down toggle & show a line of text indicating progress (eg: how many images total and how many processed along with other details) instead. Clicking the dropdown shows the details and re-clicking it hides them
- Assign: no changes here (there's another issue about simplifying the standard format of the comments section: #182)
- Upload: show the collection and location names, and the upload folder name, after the "Files ready" prompt (instead of the path to the upload). The rest of the page is OK (update details are hidden until the upload is started)

Start by locating the uploader workflow's Files, Inspect, Assign, and Upload steps and read how their current controls and progress details are presented. Implement the specified simplifications while preserving existing features; done means folder guidance, collapsible inspection details with progress text, unchanged Assign behavior, and collection, location, and folder names on Upload are all present.

Written by the indexing model from the issue text.