RESO-2736: Improve error handling with non-JSON response bodies

[ntwiles]

Two errors were mentioned in the original ticket.

• Cannot read property 'statusCode' of undefined. This is caused on line 33 by trying to read statusCode from a res which might be undefined (it will be in the case that err is truthy), since that's an error thrown locally before a request is made, and so there will be no response. The fix here is applied on line 33.

• Unexpected token < in JSON at position 1 at JSON.parse. This one is more apparent; the body in some cases us html and thus not JSON parsable. I applied a function to try to parse and to just replace with undefined if the parse fails. I don't love this solution and I'm very open to others. I assume error only happens in the case of non-200 status responses, but I applied the change for the success branch (the last if-else chain item) also just in case.