Rewrote Networking and Base Lobby Created

- Rewrote networking based on tutorials from MLAPI Demo Project and
  Dapper Dino
- Created Lobby UI based on the turorial from Dapper Dino
- Linked Existing UI into using the new networking
- Modified Lobby Settings to only allow 3 players
- Added Field for players to enter their player name

Assets/Scripts/Network/ClientGameNetPortal.cs

@@ -0,0 +1,143 @@
+using System;
+using System.Text;
+using MLAPI;
+using MLAPI.Transports.UNET;
+using UnityEngine;
+using UnityEngine.SceneManagement;
+
+[RequireComponent(typeof(GameNetPortal))]
+public class ClientGameNetPortal : MonoBehaviour
+{
+    public static ClientGameNetPortal Instance => instance;
+    private static ClientGameNetPortal instance;
+
+    public DisconnectReason DisconnectReason { get; private set; } = new DisconnectReason();
+
+    public event Action<ConnectStatus> OnConnectionFinished;
+
+    public event Action OnNetworkTimedOut;
+
+    private GameNetPortal gameNetPortal;
+
+    private UNetTransport transport;
+
+    private void Awake()
+    {
+        if (instance != null && instance != this)
+        {
+            Destroy(gameObject);
+            return;
+        }
+
+        instance = this;
+        DontDestroyOnLoad(gameObject);
+    }
+
+    private void Start() {
+        transport = NetworkManager.Singleton.GetComponent<UNetTransport>();
+
+        gameNetPortal = GetComponent<GameNetPortal>();
+
+        gameNetPortal.OnNetworkReadied += HandleNetworkReadied;
+        gameNetPortal.OnConnectionFinished += HandleConnectionFinished;
+        gameNetPortal.OnDisconnectReasonReceived += HandleDisconnectReasonReceived;
+        NetworkManager.Singleton.OnClientDisconnectCallback += HandleClientDisconnect;
+    }
+
+    private void OnDestroy()
+    {
+        if (gameNetPortal == null) { return; }
+
+        gameNetPortal.OnNetworkReadied -= HandleNetworkReadied;
+        gameNetPortal.OnConnectionFinished -= HandleConnectionFinished;
+        gameNetPortal.OnDisconnectReasonReceived -= HandleDisconnectReasonReceived;
+
+        if (NetworkManager.Singleton == null) { return; }
+
+        NetworkManager.Singleton.OnClientDisconnectCallback -= HandleClientDisconnect;
+    }
+
+    public void StartClient(string ipAddress, int port)
+    {
+        transport.ConnectAddress = ipAddress;
+        transport.ConnectPort = port;
+
+        var payload = JsonUtility.ToJson(new ConnectionPayload()
+        {
+            clientGUID = Guid.NewGuid().ToString(),
+            clientScene = SceneManager.GetActiveScene().buildIndex,
+            playerName = PlayerPrefs.GetString("PlayerName", "Missing Name")
+        });
+
+        byte[] payloadBytes = Encoding.UTF8.GetBytes(payload);
+
+        NetworkManager.Singleton.NetworkConfig.ConnectionData = payloadBytes;
+
+        NetworkManager.Singleton.StartClient();
+    }
+
+    private void HandleNetworkReadied()
+    {
+        if (!NetworkManager.Singleton.IsClient) { return; }
+
+        if (!NetworkManager.Singleton.IsHost)
+        {
+            gameNetPortal.OnUserDisconnectRequested += HandleUserDisconnectRequested;
+        }
+
+        SceneManager.sceneLoaded += HandleSceneLoaded;
+    }
+
+    private void HandleSceneLoaded(Scene scene, LoadSceneMode mode)
+    {
+        gameNetPortal.ClientToServerSceneChanged(SceneManager.GetActiveScene().buildIndex);
+    }
+
+    private void HandleUserDisconnectRequested()
+    {
+        DisconnectReason.SetDisconnectReason(ConnectStatus.UserRequestedDisconnect);
+        NetworkManager.Singleton.StopClient();
+
+        HandleClientDisconnect(NetworkManager.Singleton.LocalClientId);
+
+        SceneManager.LoadScene("TitleScene");
+    }
+
+    private void HandleConnectionFinished(ConnectStatus status)
+    {
+        if (status != ConnectStatus.Success)
+        {
+            DisconnectReason.SetDisconnectReason(status);
+        }
+
+        OnConnectionFinished?.Invoke(status);
+    }
+
+    private void HandleDisconnectReasonReceived(ConnectStatus status)
+    {
+        DisconnectReason.SetDisconnectReason(status);
+    }
+
+    private void HandleClientDisconnect(ulong clientId)
+    {
+        if (!NetworkManager.Singleton.IsConnectedClient && !NetworkManager.Singleton.IsHost)
+        {
+            SceneManager.sceneLoaded -= HandleSceneLoaded;
+            gameNetPortal.OnUserDisconnectRequested -= HandleUserDisconnectRequested;
+
+            if (SceneManager.GetActiveScene().name != "TitleScene")
+            {
+                if (!DisconnectReason.HasTransitionReason)
+                {
+                    DisconnectReason.SetDisconnectReason(ConnectStatus.GenericDisconnect);
+                }
+
+                SceneManager.LoadScene("TitleScene");
+            }
+            else
+            {
+                OnNetworkTimedOut?.Invoke();
+            }
+        }
+    }
+}