* use positional arguments in SQL functions
* only allow omitting set of last arguments in functions
* disallow omitting of a non default argument in functions
Changes compared to `/v1alpha1/graphql`
* Changed all graphql responses in **/v1/graphql** endpoint to be 200. All graphql clients expect responses to be HTTP 200. Non-200 responses are considered transport layer errors.
* Errors in http and websocket layer are now consistent and have similar structure.
