[BE][1/N]Add sharding spec logger for ShardedTensor (#99748)
Set up a nullHandler() on the OSS side.
Next step is to set up the counterpart in internal.
This is part of the effort for ShardedTensor deprecation. We want to log internal use cases for different sharding spec.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/99748
Approved by: https://github.com/H-Huang, https://github.com/fegin
