Prepare test_dtensor.py for native funcol migration (#120043)
This file contains representative tests that we would like to run with both funcol impls during the migration period. Marking them as `@run_with_both_funcol_impls`.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/120043
Approved by: https://github.com/wanchaol
ghstack dependencies: #120042
