Decouple the scaling / translation of widget views necessary in split-screen

=> We pull apart the scale and translation that are set in a fairly
   static way due to split-screen vs. the general translation and scale
   properties that might be used more dynamically, in this case
   for re-order animations
=> This allows removal of some code that breaks reorder animations
   due to the accrual of translations / scales in certain edge cases.
=> TODO in future CL: address other translation cases and make the throw
   case for calling base setTranslationX/Y for Workspace Items unconditional

issue 149438360

test: manual
Change-Id: Ic3fde172f669e215cd25db0fcd4e1c3c873d314f