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/utils.go

@@ -49,6 +49,10 @@ import (
 	"github.com/gorilla/mux"
 )
 
+const (
+	slashSeparator = "/"
+)
+
 // IsErrIgnored returns whether given error is ignored or not.
 func IsErrIgnored(err error, ignoredErrs ...error) bool {
 	return IsErr(err, ignoredErrs...)