Consider adding remove_member_cv_ref and copy_member_cv_ref

Taken from https://lists.boost.org/Archives/boost/2017/04/234374.php:

>> In "member qualifier features", I'm missing `remove_member_cv_ref` (obvious semantics) and `copy_member_cv_ref` (copies cv+ref from one member pointer to another.)

and your reply in https://lists.boost.org/Archives/boost/2017/04/234446.php:

> I'm slightly hesitant to add `remove_member_cv_ref` (`remove_member_qualifiers`?), because it doesn't quite mirror ``. Would this also remove `noexcept`/`transaction_safe`? I'm conflicted about `copy_member_cv_ref`, because I'm not sure whether it would be more useful to copy them to a function type or value type.