Max: Validate Mesh Has UVs

[moonyuet]

Changelog Description

This PR is to add the validator to check mesh has UVs in model product type.

Additional info

n/a

Testing notes:

1. Install the latest Max Addon
2. Launch Max via AYON
3. Create Model Instance with some meshes
4. Turn on Validate Mesh Has UVs in Publish Tab
5. If the mesh does not have UVs, the validator errors out.

[BigRoy]

After the last comment I think this should be good.

[LiborBatek]

When setting the Validator for UVs it correctly kicks in during Publishing of a model

when UVs are missing:

And if any sort of UVs applied (also just on selected only faces of the object) then it Validates ok and publish will succeed correctly...

[BigRoy]

Side note and not part of this PR: Just wanted to say that the Validating model content for modelMain should not be a info level log. The artist doesn't care that the validation is happening - they only need to know about data that might not be obvious or they want to double check OR any issues. This should thus be a debug log.

The project context at the top however is useful for artists however since it confirms for them that they were in the correct context, etc.