Check if the given (JSON-parsed) response body looks like a Matrix error response as specified in https://spec.matrix.org/v1.19/client-server-api/#standard-error-response
the parsed response body to check
whether the response is a valid MatrixError
Check if the given (JSON-parsed) response body looks like a Matrix error response as specified in https://spec.matrix.org/v1.19/client-server-api/#standard-error-response