OpenColorIO is missing use cases.

[andymanaws]

Use Case

Currently the submitter and adaptor only captures a specific use case - a custom config file for OCIO.

There are other use cases:

• the OCIO environment variable is used to specify the config file.
• the customer is using OCIO, but it defaulting to a stock config file ( but we must make the assumption that just because it resides in an install location, that it hasnt been manipulated away from its default value).

Proposed Solution

Add more methods to the submitter to find the OCIO config file 1> Query the environment for OCIO and use that if is exists. 2> Query is the user is utilising a config from the found search paths already available on their system( and explicitly add that). 3> Potentiall store in the template that the scene was being driven by an OCIO environment vaiablr. 4> Check that the config file specified in the above is actually a file ( additional alert for malformed OCIO environments, and to prevent a submitter crash).

add more methods to the adaptor: 1> Add the search paths for not just custom config file setups. 2> If the user has elected use an OCIO environment variable, set that OCIO environment variable with the stashed job attachment.( again this might need an update to the submitter - as this is external to Nuke at submission time, and the scene wont store this info).

[crowecawcaw]

Added in this PR: https://github.com/aws-deadline/deadline-cloud-for-nuke/pull/166