feat: implemented reconnectClient

Server/src/main/java/uulm/teamname/marvelous/server/lobbymanager/LobbyManager.java

@@ -134,6 +134,10 @@ public class LobbyManager {
         }
     }
 
+    public void restoreConnection(WebSocket connection, Participant participant) {
+        participant.setConnection(connection);
+    }
+
     /**
      * Initializes a new {@link LobbyConnection} with a not yet initialized {@link Lobby}. The {@link LobbyConnection}
      * gets some GameID, and also the sendMessageCallback and sendErrorCallback from the