Check "Show only unread articles" does not respect folder

[maurerle]

Description of the issue

Check "Show only unread articles" does not respect folder and instead shows all articles of all folders

Expected behavior

only show unread articles of the currently selected folder

Steps to reproduce

1. Have articles in a folder (and favourite read articles)
2. Tick "Show only unread articles" from 3-dot-menu
3. All articles from all folders are shown together, read and unread

Your Environment

• OCReader version: v0.48
• Nextcloud news version:
• Android version: 10