Add basic bandwidth monitoring for replication. (#10501)

This change tracks bandwidth for a bucket and object

- [x] Add Admin API
- [x] Add Peer API
- [x] Add BW throttling
- [x] Admin APIs to set replication limit
- [x] Admin APIs for fetch bandwidth

cmd/admin-router.go

@@ -214,6 +214,8 @@ func registerAdminRouter(router *mux.Router, enableConfigOps, enableIAMOps bool)
 			// -- OBD API --
 			adminRouter.Methods(http.MethodGet).Path(adminVersion + "/obdinfo").
 				HandlerFunc(httpTraceHdrs(adminAPI.OBDInfoHandler))
+			adminRouter.Methods(http.MethodGet).Path(adminVersion + "/bandwidth").
+				HandlerFunc(httpTraceHdrs(adminAPI.BandwidthMonitorHandler))
 		}
 	}