fix(typescript-fetch): Handle cors errors.

Created by: joeheyming

If there is a communication error, e.g. an OPTIONS request returns 404 not found, then the whole request is cancelled and there is no response object (it is undefined).

I observed the following error: TypeError: Cannot read properties of undefined (reading 'status') Basically response was undefined.

In order to circumvent this issue, we do a check to make sure response is "truthy", which works for objects.

With these code changes, it will throw a ResponseError, which is what you would expect instead of a TypeError.

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