BUG: Border visibility from underlying vtkScalarBar actor

Get the correct border visibility for the scalar bar
representation from the underlying scalar bar actor instead of
setting a default property. This change fixes issue 14646.

Change-Id: I7c11033475ebe8e3009bb9c3a0ebc745dbc63c23
Merge topic '14646-scalar-bar-borders' into master

20d5df76 BUG: Border visibility from underlying vtkScalarBar actor