[feature request] give some indication if a response is taken from record

In some cases, I need to know if a response comes from the record. If I see correctly, there currently is no way to do that.

[requests-cache](https://pypi.org/project/requests-cache/) does this by adding a [`.from_cache`](https://requests-cache.readthedocs.io/en/stable/modules/requests_cache.models.response.html#requests_cache.models.response.BaseResponse.from_cache) property to the response. Perhaps _responses_ could add `.from_record`.