Upgrade to .net 5

Address breaking changes from Shogi.API nuget

Gameboard.ShogiUI.Sockets/Managers/ClientActionHandlers/ListGamesHandler.cs

@@ -1,6 +1,7 @@
 using AspShogiSockets.Extensions;
 using Microsoft.Extensions.Logging;
 using Newtonsoft.Json;
+using System;
 using System.Linq;
 using System.Net.WebSockets;
 using System.Threading.Tasks;
@@ -31,16 +32,16 @@ namespace Websockets.Managers.ClientActionHandlers
         ? await repository.GetGames()
         : await repository.GetGames(userName);
 
-      var games = getGamesResponse.Games
-          .OrderBy(g => g.Players.Contains(userName))
-          .Select(g => new Game
+      var games = getGamesResponse.Sessions
+          .OrderBy(s => s.Player1 == userName || s.Player2 == userName)
+          .Select(s => new Game
           {
-            GameName = g.GameName,
-            Players = g.Players
+            GameName = s.Name,
+            Players = new[] { s.Player1, s.Player2 }
           });
       var response = new ListGamesResponse(ClientAction.ListGames)
       {
-        Games = games ?? new Game[0]
+        Games = games ?? Array.Empty<Game>()
       };
 
       var serialized = JsonConvert.SerializeObject(response);