Implement oboard diagnostics admin API (#9024)

- Implement a graph algorithm to test network bandwidth from every 
  node to every other node
- Saturate any network bandwidth adaptively, accounting for slow 
  and fast network capacity
- Implement parallel drive OBD tests
- Implement a paging mechanism for OBD test to provide periodic updates to client
- Implement Sys, Process, Host, Mem OBD Infos

cmd/rest/client.go

@@ -73,6 +73,12 @@ func (c *Client) CallWithContext(ctx context.Context, method string, values url.
 		return nil, &NetworkError{err}
 	}
 
+	final := resp.Trailer.Get("FinalStatus")
+	if final != "" && final != "Success" {
+		defer xhttp.DrainBody(resp.Body)
+		return nil, errors.New(final)
+	}
+
 	if resp.StatusCode != http.StatusOK {
 		defer xhttp.DrainBody(resp.Body)
 		// Limit the ReadAll(), just in case, because of a bug, the server responds with large data.