[quant][ao_migration] Base package in tests
Adding a base package as an argument to the testing routines.
That will allow us to test other locations that are being migrated.
For example
```
AOMigrationTestCase._test_package_import('my_mackage', base='quantization')
```
would check if `torch.quantization.my_package` and `torch.ao.quantization.my_package` are the same.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/77064
Approved by: https://github.com/jerryzh168
