chore: change str_ref_to_string to str_ref_to_owned
`ToString` is implemented by many different types than `&str`, and represents a serialization into string data. The fact that said data is returned as owned, is an implementation detail resulting from the lack of a parameter for a pre-allocated buffer.
If merely copying borrowed string data to owned string data is all that is desired, `ToOwned` is a much better choice, because if the user later refactors the code such that the input is no longer an `&str`, then they will get a compiler error instead of a mysterious runtime-behavioral change.
567a5e9ef7