application/octet-stream is associated with 3d previewer

[robkooper]

Describe the bug

The generic mime-type application/octet-stream is associated with the 3d previewer. This means all unknown files will be tried to be rendered as a 3D image with the result of showing:

To Reproduce
Steps to reproduce the behavior:

1. upload random file with no file extenson
2. go to the just uploaded file
3. See error

Expected behavior
octet-stream should not have a previewer associated.