decrease space between draggable resource and My Collections/My Groups trees

Due to the way the styling was implemented in the Choose a Location dialog (differently from how it was designed), there's a bunch of extra space between the draggable resource and the My Collections/My Groups tree nodes.

Rather than fixing to designed style (since this is actually fine as is), we should close up that extra space.

Please see the attached screenshot that shows the problem and an attached file w/ rough new spacing to be matched.

Thanks!