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/LoginPage.razor.css

@@ -0,0 +1,28 @@
+main {
+	/*display: grid;
+	grid-template-areas:
+		"header		header	header"
+		".				form		."
+		".				.				.";
+	grid-template-rows: auto 1fr 1fr;
+
+	place-items: center;
+*/
+}
+
+.LoginForm {
+	grid-area: form;
+
+	display: inline-grid;
+	grid-template-areas:
+		"errors			errors"
+		"emailLabel emailControl"
+		"passLabel	passControl"
+		"button			button";
+	gap: 0.5rem 3rem;
+}
+
+.LoginForm .Errors {
+	color: darkred;
+}
+