When a `vtkLookupTable` with `IndexedLookup` set to true
is passed to `vtkScalarBarActor`, the scalar bar is not drawn.
Instead, a set of distinct color swatches is rendered -- one
for each annotated value stored in the lookup table.
The labels stored with each annotation are not yet rendered.

Change-Id: I3849e5bf99a58ae8884f4061336545781f7b3c65