Provide built-in ACES 2.0 configs

[doug-walker]

Currently, the OCIO library provides CG and Studio configs based on ACES 1.3. There is a desire to build in updated versions based on ACES 2.0.

ACES 2.0 provides both D60 and D65 view transforms. The plan is to only build in the D65 transforms.

Here is the Milestones tracker for the work on the config generator to produce the required configs:
https://github.com/AcademySoftwareFoundation/OpenColorIO-Config-ACES/milestone/2

[doug-walker]

This was implemented for OCIO 2.5.