ADD. RadTreeView - when pressing a letter from the keyboard, the node starting with this letter should be selected.

Resolution: 
Added two new properties: KeyboardSearchEnabled and KeyboardSearchResetInterval. When set the KeyboardSearchEnabled property to true, user can navigate to an item by typing when RadTreeView is focused. 
You can set how long the user must wait before searching with the keyboard is reset using the KeyboardSearchResetInterval property.