Refactor test for unique and unique_consecutive and fix some bugs (#31211)
Summary:
Tests for unique_dim will be refactored in a separate PR.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/31211
Differential Revision: D19034968
Pulled By: ngimel
fbshipit-source-id: 855d326b37638b5944f11fbbce03394cf000daf9
