Add AOV test scenes

[dictoon]

[techytoes]

@dictoon I want to work on this issue. Can you please help me with the same? I need a little help I'm relatively new to this organisation.

[oktomus]

When saving the output, aovs get written. The runtestsuite.py script should look for a reference image for all written images.

To look for all written images, we can simply start by looking for all possible file names (for each AOV type).

What should we do if a AOV is written but no reference image exists ? In this case, I think we should consider the test as failed with message "Missing additional reference image".

[dictoon]

I think we should simply do for AOVs what we already do for beauty.