VOLTHA/VOL-3478 : FlowId are logged as decimals and reported by voltctl as hex.

By Default flow-id would be in int format .
hex-id option is supported to display flow id in hex format.

Change-Id: I8b715613a6800b89a5dcedb8b90dc289b336bf24
diff --git a/internal/pkg/commands/flows.go b/internal/pkg/commands/flows.go
index efe09f2..1e8ec62 100644
--- a/internal/pkg/commands/flows.go
+++ b/internal/pkg/commands/flows.go
@@ -28,6 +28,7 @@
 
 type FlowList struct {
 	ListOutputOptions
+	FlowIdOptions
 	Args struct {
 		Id string `positional-arg-name:"DEVICE_ID" required:"yes"`
 	} `positional-args:"yes"`
@@ -143,7 +144,7 @@
 	data := make([]model.Flow, len(flows.Items))
 	var fieldset model.FlowFieldFlag
 	for i, item := range flows.Items {
-		data[i].PopulateFromProto(item)
+		data[i].PopulateFromProto(item, options.HexId)
 		fieldset |= data[i].Populated()
 	}