Max: Add missing workfile creator

[moonyuet]

Changelog Description

Add the missing workfile creator in 3dsMax.

Additional info

For some reason, get_subset_name function can't set the name with the correct variant, although there is variant.
It is using the old subset name workfileAsset.

Testing notes:

1. Launch Max via launcher
2. Load Scene
3. Open publisher
4. it should automatically create the workfile instance
5. you can notice the new container (which is hidden and greyed out) named accordingly
6. Publish workfile
7. It should be successfully published.

[antirotor]

Is it the same code that was merged to ayon-core?

[moonyuet]

Is it the same code that was merged to ayon-core?

yes it is. the ayon_core version is already merged.