IdentifyBuiltinColorSpace heuristics failure edgecases: ACEScc, ADX16, CIE-XYZ-D65

Apparently, ACEScc, ADX16, and both CIE XYZ-D65 spaces from ocio://studio-config-latest (as of OCIO v2.5.0) are evading our out-of-the-box matching / identification algorithms.

I've been noticing that, very occasionally, Config::IdentifyBuiltinColorSpace has trouble matching certain color spaces among configs that really do share functionally identical definitions, and should, by all accounts, be recognized as equivalent.

I wrote a little function to assess which color spaces in a given config IdentifyBuiltinColorSpace seems to have the most trouble with -- essentially, I'm using the exact same config for both the srcConfig and the builtinConfig, and just collecting the color spaces that can't be found in their own configs.

In exploring this, I found that both optimization flags (unsurprisingly) and color space visibility (surprisingly) affect the rate of success.

Insights:
- It would be useful if there were a way to force Config.IdentifyBuiltinColorSpace to always attempt to failover to searching inactive color spaces.
- It would be nice if IdentifyBuiltinColorSpace exposed an optional optimizationFlags argument as a means of fine-tuning the equivalency "tolerance"

Findings:
- "ADX16" color spaces based off of the `ADX16_to_ACES2065-1` BuiltinTransform can be matched when using DRAFT optimization or higher
- "ACEScc" and "ACESproxy10i" color spaces based off of the `ACEScc_to_ACES2065-1` `ACESproxy10i_to_ACES2065-1` BuiltinTransform styles respectively remain "unmatchable", regardless of optimization settings.

Here's a python snippet if you wanna mess around:

```python
import PyOpenColorIO as ocio
import os

def get_unmatchable_color_spaces(
config: ocio.Config,
optimization: ocio.OptimizationFlags | int | None = None,
exclude_inactive: bool = False,
verbose: bool = False,
) -> list[str]:

# Optimization Flags affect the identification heuristics. The API doesn't expose a way
# to directly control the optimization flags used for identifying color spaces, but we
# can temporarily adjust the $OCIO_OPTIMIZATION_FLAGS environment variable
# if we want to temporarily override the global optimization behavior

# Preserve the previous environment to restore later.
prev_env = dict(os.environ)
if optimization:
# Temporarily set $OCIO_OPTIMIZATION_FLAGS to the requested value.
os.environ[ocio.OCIO_OPTIMIZATION_FLAGS_ENVVAR] = str(int(optimization))

# Color space visiblity affects the identification heuristics.
# To maximize the likelihood of finding a match, we can temporarily
# activate all color spaces.

# Store the old inactive color spaces to restore later.
old_invisible_color_spaces = config.getInactiveColorSpaces()

if not exclude_inactive:
# Temporarily make all color spaces visible.
config.setInactiveColorSpaces("")

# Iterate over all the color spaces in the config, and collect names of
# color spaces that steadfastly refuse to be matched!
problem_spaces = []
for cs_name in config.getColorSpaceNames(
ocio.SEARCH_REFERENCE_SPACE_ALL,
ocio.COLORSPACE_ALL
):
# Try to match each color space in the config to... itself!
try:
matched_space = ocio.Config.IdentifyBuiltinColorSpace(config, config, cs_name)
except ocio.Exception as e:
if verbose:
ocio.LogMessage(ocio.LOGGING_LEVEL_WARNING, str(e))
problem_spaces.append(cs_name)

# Cleanup -- restore the previous environment and config state.`
os.environ.clear()
os.environ.update(prev_env)
config.setInactiveColorSpaces(old_invisible_color_spaces)

return sorted(problem_spaces)
```

```python
studio_config_modified = ocio.Config.CreateFromFile("ocio://studio-config-latest")

# Add an ACESproxy10i color space to the studio-config, because I suspect it'll also fail to match itself.
studio_config_modified.addColorSpace(
ocio.ColorSpace(
ocio.REFERENCE_SPACE_SCENE,
name="ACESproxy10i",
toReference= ocio.BuiltinTransform("ACESproxy10i_to_ACES2065-1")
)
)

print(f"""
Unmatchable color spaces: {studio_config_modified.getName()}
---

- Default IdentifyBuiltinColorSpace behavior:
{get_unmatchable_color_spaces(studio_config_modified, exclude_inactive=True)}

- Ignore visibility + no optimizations:
{get_unmatchable_color_spaces(studio_config_modified, optimization=ocio.OPTIMIZATION_NONE)}

- Ignore visibility + draft optimizations:
{get_unmatchable_color_spaces(studio_config_modified, optimization=ocio.OPTIMIZATION_DRAFT)}
""")
```

```

Unmatchable color spaces: studio-config-v4.0.0_aces-v2.0_ocio-v2.5
---

- Default IdentifyBuiltinColorSpace behavior:
['ACEScc', 'ACESproxy10i', 'ADX16', 'CIE XYZ-D65 - Display-referred', 'CIE XYZ-D65 - Scene-referred']

- Ignore visibility + no optimizations:
['ACEScc', 'ACESproxy10i', 'ADX16']

- Ignore visibility + draft optimizations:
['ACEScc', 'ACESproxy10i']
```

Commencez par exécuter la reproduction Python fournie contre ocio://studio-config-latest et comparez les résultats de IdentifyBuiltinColorSpace selon les indicateurs d’optimisation et les paramètres d’espaces colorimétriques inactifs. Examinez ensuite Config::IdentifyBuiltinColorSpace ainsi que les chemins de matching de ACEScc, ADX16 et CIE XYZ-D65 BuiltinTransform. C’est terminé lorsque les espaces colorimétriques équivalents listés sont identifiés de manière cohérente et que le comportement demandé en matière de visibilité et d’optimisation est couvert.

Rédigé par le modèle d'indexation à partir du texte de l'issue.