Logic for multiple models with `!useTransferFunction` and `!useColorMap`

Each tab in the `` will effectively be empty, the only thing the user can change is `enabled`. What should be displayed inside the tab?

Start by inspecting the tabs and the logic for models where !useTransferFunction and !useColorMap are true. Clarify what each otherwise-empty tab should display beyond the enabled control, then define the expected behavior before implementation; the issue currently provides no file, test, or concrete acceptance criteria.

Written by the indexing model from the issue text.