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.Database/Session/Stored Procedures/SetPlayer2.sql

@@ -1,16 +1,13 @@
 CREATE PROCEDURE [session].[SetPlayer2]
-	@SessionName [session].[SessionName],
-	@Player2Name [user].[UserName] NULL
+	@SessionId [session].[SessionSurrogateKey],
+	@PlayerId [dbo].[AspNetUsersId]
 AS
 BEGIN
 	SET NOCOUNT ON;
-
-	DECLARE @player2Id BIGINT;
-	SELECT @player2Id = Id FROM [user].[User] WHERE [Name] = @Player2Name;
-
-	UPDATE sess
-	SET Player2Id = @player2Id
-	FROM [session].[Session] sess
-	WHERE sess.[Name] = @SessionName;
+	
+	UPDATE [session].[Session]
+	SET Player2Id = @PlayerId
+	FROM [session].[Session]
+	WHERE Id = @SessionId;
 
 END