DUI: remove key navigation from library view.

Priority: _Critical_
Suddenly, I found out, that LibraryView should not have any navigation. So, I created `PreviewKeyDown` to handle key down.

Reviewers
@Benglin ,@vmoyseenko, please take a look.

Link to YouTrack:
[MAGN-5241](http://adsk-oss.myjetbrains.com/youtrack/issue/MAGN-5241) DUI: Disable navigation for regular view