Replace custom socket implementation with SignalR.

Replace MSAL and custom cookie auth with Microsoft.Identity.EntityFramework
Also some UI redesign to accommodate different login experience.

Shogi.UI/Pages/Play/GameBoard/EmptyGameBoard.razor

@@ -0,0 +1,6 @@
+@using Contracts.Types;
+
+<GameBoardPresentation Perspective="WhichPlayer.Player1" />
+
+@code {
+}