Fix incorrect state value in image/file/video import status docs

[HannesLinde]

Relations:

• Issue: conversation with Slack
• Related PRs: n/a

Motivation

The import-status endpoint docs for images, files, and videos showed an example where an individual entry's state is "success". The server never returns that value for a single entry — per-entry state can only be imported, skipped, or failed (success is only ever the top-level/batch state). This corrects the misleading example across all three docs.

Changelog

• 🐞 Fix incorrect example state: success for an individual entry in the image, file, and video import-status docs (import-images-status.yaml, import-files-status.yaml, import-videos-status.yaml) — corrected to state: imported to match actual server behavior