From https://github.com/catapult-project/catapult/issues/4108

V2spa currently does not display any error messages.
All callers of RequestBase subclasses should display errors when the response status >= 400 or the request times out, except TimeseriesRequest 404, which is expected.

 * SessionStateRequest
 * SessionIdRequest
 * TimeseriesRequest
 * AlertsRequest
 * ReportRequest
 * DescribeRequest
 * TestSuitesRequest
 * SheriffsRequest
 * ReportNamesRequest