Filebrowser

The mouse click handle on file favorites updating the selected parent of the navigation state was replaced with a listener.

The file browser list view was updated to include
- icons
- file size
- mime type of files
An empty string is not so nice as a value for "nothing". Because without looking at the code I wouldn't even have guessed that the method might not be able to get the mime type. Use `Optional<String>` instead.