BUG: change fiducial place icon to have arrow point at top

The previous icon had the fiducial glyph at the top of the icon
and was leading to a feeling that the fiducial was off by a few
pixels when placed with the mouse. Using a copy of the
Annotations point with arrow icon.
BUG: revert node tag name change

It was conflicting with vtkMRMLFiducialListNode and the Markups fiducial
node wasn't set up to read the fiducial list node XML attributes as
it should do if it's over riding that xml node tag.