Move as_strided_copy template to copy_ops_util (#2216)

Summary:
Pull Request resolved: https://github.com/pytorch/executorch/pull/2216

bypass-github-pytorch-ci-checks
ghstack-source-id: 217233089
exported-using-ghexport

bypass-github-export-checks

Reviewed By: SS-JIA

Differential Revision: D53624735

fbshipit-source-id: b04b3835e0683f4e414a8ecba435fecfc007fe8d