Multi-block with explicit transparency of 1 and actor transparency displays incorrectly

This is a follow-on to #20251 (closed)

If I have a multi-block and I set an opacity == 1 in the multi-block inspector, and add transparency on the actor, it disappears.

Steps to reproduce:

• Add two sphere sources, (one offset to x = 0.5)
• Select both, apply the Group Datasets filter.
• Open the multi-block inspector, choose one sphere, double-click to change the opacity, but leave it set at 1
• Select the multi-block, choose Properties .. Styles .. Opacity and change to less than 1. Result: the sphere with opacity set to 1 disappears.

We are hitting this issue in AEVA application in the CMB group, which is a paraview-derived app. aeva/aeva#98 (closed)