- added status field to SP result messages

git-svn-id: https://gnunet.org/svn/gnunet@33217 140774ce-b5e7-0310-ab8b-a85725594a96
- proper service-side error reporting for the SP API

git-svn-id: https://gnunet.org/svn/gnunet@33218 140774ce-b5e7-0310-ab8b-a85725594a96