Add support for UV transform value exports

[dgovil]

This commit adds support for UV transform exports.
We have not yet implemented the import functionality.

[dgovil]

Apologies, the test is failing due to default maya plugins again. I'll fix up the Maya file and and try and institute better validation checks on our side to make sure we aren't committing files with other plugins.

# Traceback (most recent call last):
    #   File "<maya console>", line 1, in <module>
    # RuntimeError: Plug-in, "mtoa", was not found on MAYA_PLUG_IN_PATH.

[dgovil]

Okay I've removed mtoa and any .ai_* setattrs. That should satisfy the CI setup I hope.
I'm not sure I can kick off a new CI by myself, but hopefully should work for whenever you do it.

[kxl-adsk]

Started one. You will as well notice that we have clang-format check as well.

[dgovil]

Started one. You will as well notice that we have clang-format check as well.

Thanks! and yes, that format check will be handy (and I'm glad to see this PR passed it)

[dgovil]

Looks like the CI failed getting results back

fatal: could not read Username for 'https://github.com': No such device or address

[kxl-adsk]

That’s new. I will start it again.

[kxl-adsk]

@dgovil There was an incident with GitHub yesterday - could be related - https://www.githubstatus.com/incidents/sxthxvdlljk4

New PF passed.

[dgovil]

Ah makes sense. Thanks for looking into it too!

[kxl-adsk]

Credit goes to @smithw-adsk

[mattyjams]

Mostly looks good to me! Just two small suggestions for the new code.

In the test though, I'm a little unclear about the use of maya.standalone. I would think that we do want to initialize with the fixturesUtils.setUpClass() call, and then uninitialize() in tearDownClass()?

[dgovil]

@mattyjams Thanks for the suggestions. Addressed that and pushed a new commit with all the changes.

[mattyjams]

Looks great now! Thanks @dgovil!

[kxl-adsk]

@dgovil You PR is almost ready to go in, just please address the clang-format-lint check error.

[dgovil]

@kxl-adsk Done.