HDR display support -- HDR compatible configs

[doug-walker]

As presented at the Siggraph BoF, we propose having a set of characteristics that configs must support to be considered "HDR display compatible".

The proposed characteristics are:

• Must the set cie_xyz_d65_interchange role to allow applications to convert to OS-required space
• Must use display color spaces
• Must set interop_id on display color spaces
• Must include the hdr_virtual_display (see forthcoming proposal)

A new function Config::isHdrDisplayCompatible() will be provided for applications to use.

The ociocheck command-line tool will be upgraded to report if a config is HDR display compatible.

Parent issue: #1996.

[doug-walker]

Given that what constitutes "HDR Display compatible" may change over time, I'd like to revise the above proposal to add a more generic function Config::checkConfigCompatibility(ConfigFeatureSet), where the argument would be a new enum that could be used to check various features/capabilities that get added over time.

The first enum could be something like CONFIG_HDR_DISPLAY_SUPPORT_26, where the numerals at the end indicate that it is checking for whatever constitutes HDR Display support as of OCIO 2.6.