Display: (Assign Files) The + button remains active even after media files have been assigned to the display

[ifarzana]

In the Display -> Assign Files section, the + button remains active even after media files have been assigned to the display. This allows users to add the same media multiple times, which is not the intended behaviour.

Expected Behaviour:

Once the media file is added to the display, further additions of the same file should be prevented.

Actual Behaviour:

• Users can click the + button multiple times to add the same media files or layouts repeatedly.
• This functionality does not cause any errors as files are only downloaded once.
  

Steps to Reproduce:

1. Navigate to Display.
2. Select a display then click on Assign Files from the row menu.
3. Click the + button to add the selected file.
4. Notice that the + button remains active and allows additional additions of the same file.