Improve TORCH_LOGS settings error msg (#97264)
Lists registered loggable entities if an invalid settings string is passed via TORCH_LOGS
[before](https://gist.github.com/mlazos/91fcbc3d577f874bcb3daea44f8b41f2)
[after](https://gist.github.com/mlazos/815ea9e76aca665602228f960e0eb0d6)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/97264
Approved by: https://github.com/ezyang, https://github.com/jansel
