client_create_request_builder should return a RequestBuilderWrapper even on error #15
Description
Currently, the client_create_request_builder returns a null RequestBuilderWrapper reference if the client cannot create the request builder, e.g. due to an invalid URL. There is no error message about why the request builder could not be created. A solution is need for this.
We must also consider that a client reference can be used in parallel to create multiple requests. As such, the error needs to be associated with the specific call to client_create_request_builder that failed. Since there is already an error message field inside of the RequestBuilderWrapper struct, we could change the behavior of client_create_request_builder such that it always returns a RequestBuilderWrapper reference and includes the error information in the error message field (but with a null request builder reference in it's internal field for storing the request builder). That would allow LabVIEW to call the existing function to read error information on the RequestBuilder object.