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/Layout/MainLayout.razor.css

@@ -0,0 +1,5 @@
+.MainLayout {
+	display: grid;
+	grid-template-columns: auto 1fr;
+	place-items: stretch;
+}