Hotfix/npm ckeditor module

[jurra]

Two major problems have been solved

Ckeditor not working offline (Partially solved)

• I had to replace the hardocs-ck-editor with the classic ckeditor.
• The MathType module is giving problems offline, see: https://github.com/ckeditor/ckeditor5/issues/6494

Fixed bug that was deleting a file when saved intermitently

This bug was claimed to be fixed in commit daf6d6a8ec4e616e03d32db66fc8e2a943ea7ca8. But it was still there, I got feedback from a user on Friday reporting the exact behavior we were facing previously.