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/PlayerName.razor

@@ -0,0 +1,21 @@
+<p style="margin: 0">
+	@if (IsTurn)
+	{
+		<span>*&nbsp;</span>
+	}
+
+	@if (string.IsNullOrEmpty(Name))
+	{
+		<span>Empty Seat</span>
+	}
+	else
+	{
+		<span>@Name</span>
+	}
+
+</p>
+
+@code {
+	[Parameter][EditorRequired] public bool IsTurn { get; set; }
+	[Parameter][EditorRequired] public string Name { get; set; } = string.Empty;
+}