TreeViewImpl#select should cause selected item to be scrolled onto the screen

This makes the interface appear broken in many cases.

• When you follow a favorite, or a bookmark to a location in the tree, the item may not be visible.
• When you are done moving an item, you may not see the moved item on screen.

I dont think the comment in the code is accurate:
// do not #setCurrentPageFirstItemId because AbstractJcrContainer's index resolution is super slow.
But I did try using vaadin setCurrentPageX methods and this did not work as expected.