vtkScalarBarActor: in vertical mode, add option to rotate title so it is aligned vertically
Add an option to vtkScalarBarActor to orient the title with the color legend when the legend is oriented vertically. The image below, from ParaView, shows the desired result.
For reference, ParaView's scalar bar is implemented in a different class whose API documentation is here. It by default orients the title vertically and provides an option to force the title to be horizontal using a ForceHorizontalTitle boolean property. There is no requirement to make the API match, but it is here as a consideration.