API: Add user online stats (#3637)

* add statsUserOnline bool to policy

* add OnlineMap struct to stats

* apply UserOnline functionality to dispatcher

* add statsonline api command

* fix comments

* Update app/stats/online_map.go

Co-authored-by: mmmray <142015632+mmmray@users.noreply.github.com>

* improve AddIP

* regenerate pb

---------

Co-authored-by: mmmray <142015632+mmmray@users.noreply.github.com>

features/policy/policy.go

@@ -27,6 +27,8 @@ type Stats struct {
 	UserUplink bool
 	// Whether or not to enable stat counter for user downlink traffic.
 	UserDownlink bool
+	// Whether or not to enable online map for user.
+	UserOnline bool
 }
 
 // Buffer contains settings for internal buffer.
@@ -123,6 +125,7 @@ func SessionDefault() Session {
 		Stats: Stats{
 			UserUplink:   false,
 			UserDownlink: false,
+			UserOnline:   false,
 		},
 		Buffer: defaultBufferPolicy(),
 	}