Add support for client-side replays (#4122)

Robust.Client/GameObjects/ClientEntityManager.cs

@@ -10,6 +10,7 @@ using Robust.Shared.IoC;
 using Robust.Shared.Log;
 using Robust.Shared.Network;
 using Robust.Shared.Network.Messages;
+using Robust.Shared.Replays;
 using Robust.Shared.Utility;
 
 namespace Robust.Client.GameObjects
@@ -24,6 +25,7 @@ namespace Robust.Client.GameObjects
         [Dependency] private readonly IClientGameTiming _gameTiming = default!;
         [Dependency] private readonly IClientGameStateManager _stateMan = default!;
         [Dependency] private readonly IBaseClient _client = default!;
+        [Dependency] private readonly IReplayRecordingManager _replayRecording = default!;
 
         protected override int NextEntityUid { get; set; } = EntityUid.ClientUid + 1;
 
@@ -184,6 +186,12 @@ namespace Robust.Client.GameObjects
             switch (message.Type)
             {
                 case EntityMessageType.SystemMessage:
+
+                    // TODO REPLAYS handle late messages.
+                    // If a message was received late, it will be recorded late here.
+                    // Maybe process the replay to prevent late messages when playing back?
+                    _replayRecording.RecordReplayMessage(message.SystemMessage);
+
                     DispatchReceivedNetworkMsg(message.SystemMessage);
                     return;
             }