Rework sync procedure and add a loading indicator

The server will now send a sync message when the client connects via WebSocket. This removes the need to send another GET request to sync game data.

TableturfBattleServer/DataStructures.cs

@@ -0,0 +1,44 @@
+using Newtonsoft.Json;
+
+namespace TableturfBattleServer.DTO;
+
+internal class WebSocketPayload<T> {
+	[JsonProperty("event")]
+	public string EventName;
+	[JsonProperty("data")]
+	public T Payload;
+
+	public WebSocketPayload(string eventName, T payload) {
+		this.EventName = eventName ?? throw new ArgumentNullException(nameof(eventName));
+		this.Payload = payload;
+	}
+}
+internal class WebSocketPayloadWithPlayerData<T> : WebSocketPayload<T> {
+	[JsonProperty("playerData")]
+	public PlayerData? PlayerData;
+
+	public WebSocketPayloadWithPlayerData(string eventName, T payload, PlayerData? playerData) : base(eventName, payload)
+		=> this.PlayerData = playerData;
+}
+
+public class PlayerData {
+	[JsonProperty("playerIndex")]
+	public int PlayerIndex;
+	[JsonProperty("hand")]
+	public Card[]? Hand;
+	[JsonProperty("deck")]
+	public Card[]? Deck;
+	[JsonProperty("move")]
+	public Move? Move;
+	[JsonProperty("cardsUsed")]
+	public List<int>? CardsUsed;
+
+	public PlayerData(int playerIndex, Card[]? hand, Card[]? deck, Move? move, List<int>? cardsUsed) {
+		this.PlayerIndex = playerIndex;
+		this.Hand = hand;
+		this.Deck = deck;
+		this.Move = move;
+		this.CardsUsed = cardsUsed;
+	}
+	public PlayerData(int playerIndex, Player player) : this(playerIndex, player.Hand, player.Deck, player.Move, player.CardsUsed) { }
+}