BUG: Fixed translation sliders in local coordinate reference mode.

In local coordinate reference mode the slider positions do not match
directly with the transformation matrix values.

Similarly to rotation sliders, only relative positions are set
with the sliders in local coordinate reference mode.

Fixes #3488

From: Andras Lasso <lasso@queensu.ca>

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22713 3bd1e089-480b-0410-8dfb-8563597acbee