This task will add options shading pop-over when using cycles in the viewport.
Details depends on what is being discussed in T68312: LookDev & Eevee Preview.
Here is a node graph that supports these features.
The Rotation maps to the Mapping Rotation-Z
The Background slider maps to the Background value
The Studiolight HDRI maps to the Environment Texture.
A future requirement is to change the Strength of the background. This can be connected to the Intensity node.

