Replace ClientResponseError.code with .status

[asvetlov]

To keep similarity with response classes.
.code should be a deprecated property.

The issue is trivial, volunteer is welcome.

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a [new issue] for related bugs.
If you feel like there's important points made in this discussion, please include those exceprts into that [new issue].
[new issue]: https://github.com/aio-libs/aiohttp/issues/new