Make `run_binary_ops_test` function generic and Add tests to add_kernel function (#42101)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/42101
1. Add test fixture `atest class` to store global variables
2. Make `run_binary_ops_test` function generic: can dispose different dtypes and different numbers of parameters
3. add test to `add_kernel`
Test Plan:
Run locally to check cover the corresponding code part in `BinaryOpsKernel.cpp`.
CI
Reviewed By: malfet
Differential Revision: D22760015
fbshipit-source-id: 95b47732f661124615c0856efa827445dd714125
