Change how max_lag is calculated and reported (#14378)

-Change how max_lag is calculated and reported

- Cap singleplayer step at 60Hz

- Clarify dedicated_server_step

src/server.h

@@ -609,12 +609,14 @@ private:
 	MutexedVariable<std::string> m_async_fatal_error;
 
 	// Some timers
+	float m_time_of_day_send_timer = 0.0f;
 	float m_liquid_transform_timer = 0.0f;
 	float m_liquid_transform_every = 1.0f;
 	float m_masterserver_timer = 0.0f;
 	float m_emergethread_trigger_timer = 0.0f;
 	float m_savemap_timer = 0.0f;
 	IntervalLimiter m_map_timer_and_unload_interval;
+	IntervalLimiter m_max_lag_decrease;
 
 	// Environment
 	ServerEnvironment *m_env = nullptr;
@@ -662,12 +664,6 @@ private:
 	// The server mainly operates in this thread
 	ServerThread *m_thread = nullptr;
 
-	/*
-		Time related stuff
-	*/
-	// Timer for sending time of day over network
-	float m_time_of_day_send_timer = 0.0f;
-
 	/*
 	 	Client interface
 	*/