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/Identity/RegisterPage.razor.css

@@ -0,0 +1,15 @@
+.LoginForm {
+	grid-area: form;
+	display: inline-grid;
+	grid-template-areas:
+		"errors				errors"
+		"emailLabel		emailControl"
+		"passLabel		passControl"
+		"confirmLabel	confirmControl"
+		"button				button";
+	gap: 0.5rem 3rem;
+}
+
+	.LoginForm .Errors {
+		color: darkred;
+	}