Backport improvements

[saintdev]

• [x] Add QueryParams for better handling of query parameters
• [x] Factor out build_request()
• [x] Factor out deserialize_response()
  • [x] Add error type for deserialize_response() that passes through the json::Value, HTTP status code and type name.
• [x] Add ApiError::Response that preserves the url of the response error
• [x] builder() method lifetime is independent of endpoint lifetime
• [x] Default to Method::GET for Endpoint::method()
• [ ] Testing [TBD]