cli: Wrap Err stream

This wraps the cli stderr stream the same way as stdin and stdout, which
extends the stream with TTY-related methods.

Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>

cli/command/telemetry_utils_test.go

@@ -136,7 +136,7 @@ func TestStdioAttributes(t *testing.T) {
 			cli := &DockerCli{
 				in:  streams.NewIn(io.NopCloser(strings.NewReader(""))),
 				out: streams.NewOut(outBuffer),
-				err: errBuffer,
+				err: streams.NewOut(errBuffer),
 			}
 			cli.In().SetIsTerminal(tc.stdinTty)
 			cli.Out().SetIsTerminal(tc.stdoutTty)