fix: handle html server response

[shetzel]

What does this PR do?

Handles an HTML response from the server and throws a helpful error. Also, if the error is just a string or doesn't have the data property set it handles it as well.

What issues does this PR fix or reference?

@W-14756399@

[mshanemc]

QA: using yarn:link of this branch into plugin-auth

./bin/dev.js org login device --instance-url https://computing-connect-6970-dev-ed.scratch.my.salesforce.com/services/data/v50.0
Error (1): HTTP response contains html content. Check that the org exists and can be reached.

✅ good human error message
✅ json output contains the full html response in its data property.

❓ exitCode is 1.