Possible duplicates in the list of links

1. Add link to an empty folder.
2. Duplicate the link file in the folder.
3. Reload the app.
4. List shows the same link twice.

The app should filter links with the same Id.

Reproduce the four steps in the Android app, then trace where links are assembled for the list and where their IDs can be compared. Done means duplicated link files with the same ID produce only one entry after reload; no file or test is named in the issue.

Written by the indexing model from the issue text.