Enable setting a separate range for the scalar opacity map
Adds separate controls for setting the opacity range. Since each transfer function has an associated scalar opacity function, we always show the separate controls for the opacity range. Representations that use the scalar opacity function in rendering will use this separate range.
In the GUI, this control looks like
Changes to the scalar opacity function range are recorded in Python traces and stored/restored to/from statefiles.
Closes #20048 (closed)