move GetDimFromOrderString to caffe2/core/types.h (#25671)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/25671
To decouple string_utils.h from types.h and protobuf headers.
Logically GetDimFromOrderString seems to be more similiar to
StringToStorageOrder comparing to other string_utils functions.
Test Plan: - Will check all internal/external CI jobs.
Reviewed By: yinghai
Differential Revision: D17191912
Pulled By: ljk53
fbshipit-source-id: fe555feef27bfd74c92b6297c12fb668252ca9ff
