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.Contracts/Types/SessionMetadata.cs

@@ -1,8 +1,11 @@
-namespace Shogi.Contracts.Types
+using System;
+
+namespace Shogi.Contracts.Types
 {
-  public class SessionMetadata
-  {
-    public string Name { get; set; }
-    public int PlayerCount { get; set; }
-  }
+	public class SessionMetadata
+	{
+		public Guid SessionId { get; set; }
+		public string Player1 { get; set; } = string.Empty;
+		public string Player2 { get; set; } = string.Empty;
+	}
 }