On rejection Error.message is empty if statusText is empty

[gillchristian]

Found out about it while investigating #226

trae/lib/helpers/response-handler.js

Line 45 in fa83b7f

const err = new Error(response.statusText);

We should have a default error message.

Also, since the Error has its own .toString debugging of the response is not ideal, all the properties are not displayed. We could think about our own .toString for the ResponseError that we are going to use in v2