Ability to override unsupported materials

On behalf of forum user Jpjapers.

Original thread: https://forum.corona-renderer.com/index.php?topic=42553.0

The user would like to be able to temporarily override all unsupported materials in scene just like currently it is possible to override all scene materials in Render Setup > Scene.

"Use case: I;ve imported a ton of revit models and im halfway through processing them for new materials. I need to render out an image to show the progress and check my materials but because of the unsupported materials that are yet to be processed the render looks a mess, the reflections are full of red and the image is affected far too much for me to be able to reliably check anything.

Previously proposed solutions: I could run the converter but sometimes this again leads to unwanted results with things like metals and self-illuminating materials

The red illuminated material is very useful for identifying objects that need fixing and that's why i don't want to actually remove the ability to use that, it just needs a temporary override in some situations."