Maya: Remove duplicate plugin

[tokejepsen]

Changelog Description

The two plugins below are doing the same work, so we can remove the one focused solely on lookdev.

https://github.com/ynput/OpenPype/blob/develop/openpype/hosts/maya/plugins/publish/validate_look_members_unique.py
https://github.com/ynput/OpenPype/blob/develop/openpype/hosts/maya/plugins/publish/validate_node_ids_unique.py

Testing notes:

1. Setup lookdev in Maya duplicate cbids, by duplicating a mesh after cbid has been created.
2. Publish and validate should pick up the non-unique cbids.

[moonyuet]

Looks good for me but having tested the code.
And the two validators do check exactly the same unique ids in the instance, we can just combine into one instead.

[BigRoy]

I believe you are correct - I did not test it however.

[LiborBatek]

The Validator works as expected and kicks in when duplicate ID objects found in the asset.