GitLab

* add tests for matmul and sharding-matmul benchmarks.

* add decorator for sharding_matmul tests.

* add __init__.py for utils of benchmarks tests.

* disable GPU tests for CPU platform validation.

* fix typo
Co-authored-by: Guoshuai Zhao <guzhao@microsoft.com>
Co-authored-by: Peng Cheng <chengpeng5555@outlook.com>
Co-authored-by: Yifan Xiong <yifan.xiong@microsoft.com>