new 'Scan this folder' feature doesn't work correctly

Description

1. The new feature 'Scan this folder' does add the files into the ML but doesn't give the information in the file browser (no cover thumbnails) and the info card (no time label) when scanned. The whole media library isn't scanned at default (clean install). On the info card the 'not scanned' status doesn't disappear when the folder was scanned and the info card is opened again on the same file. But we don't need this entry on the info card at all because we have this option on every folder in the explorer now:
   
   
2. The option in the above folder menu should have a checkbox which can toggle if possible to add/remove folder from scan:
   
3. The option 'Copy to clipboard' is not needed on folders. An already scanned folder should get an entry like: 'Remove this folder from scanning'.
   

Steps to reproduce

1. do not scan the ML on first start in the wizard
2. open info card on a not scanned file
3. open the context menu of a folder

Context

App version

3.3.0 nightly

Android version

9

Device model

one plus one