Close response body middleware log is not clear

In `middleware_close_response_body.go`, if we fail to copy the response body or close the response body, we couldn't see the error from the log.
Code url: https://github.com/aws/smithy-go/blob/main/transport/http/middleware_close_response_body.go#L65-L76

Start in middleware_close_response_body.go at lines 65-76 and inspect the logging paths for response-body copy and close failures. Update the relevant log output so both errors are visible, then verify that the close-response-body middleware reports the failure details when either operation fails.

Written by the indexing model from the issue text.