Propagate preview window selection to sources list
Fix wrong selection of items near origin in the preview window

If you have an item with width = 0 and height = 0 close to (0, 0)
clicking anywhere in the preview window would select them
Do not draw selected item outline if selected item is invisible

This should probably be revisited if the preview can be rotated in 3D,
or someone comes up with a good 3D manipulation idea for the preview