Feature request: provide option to turn `TryUnwrapError<&Self>` into `TryUnwrapError<Self>`

[atezet]

In order to be able to pass the TryUnwrapError along with another error, it would be useful to be able to have some sort of input_to_owned method on TryUnwrapError to turn the input wrapped by the error into an owned type. Another option would be to be able to annotate the enum to provide an error wrapping owned Self for _ref and _mut methods in the first place.