implement `JU`

src/CommandHandlers/JoinUserHandler.cs

@@ -0,0 +1,32 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using sodoffmmo.Attributes;
+using sodoffmmo.Core;
+using sodoffmmo.Data;
+
+namespace sodoffmmo.CommandHandlers
+{
+    [ExtensionCommandHandler("JU")]
+    public class JoinUserHandler : CommandHandler
+    {
+        public override Task Handle(Client client, NetworkObject receivedObject)
+        {
+            string mpId = receivedObject.Get<NetworkObject>("p").Get<string>("0");
+
+            if (mpId != null)
+            {
+                Room? room = Room.AllRooms().FirstOrDefault(e => e.Id == Int32.Parse(mpId));
+
+                if (room != null)
+                {
+                    client.SetRoom(room);
+                }
+            }
+
+            return Task.CompletedTask;
+        }
+    }
+}