[DTensor] Enable ASGD foreach optimizer and add the associated unit test (#121942)
Enable ASGD foreach optimizer and add DTensor optimizer unit test for ASGD.
Note that we need to investigate why when using ASGD we need higher atol and rtol when comparing model parameters. Listing it as a TODO now.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/121942
Approved by: https://github.com/wanchaol