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/Layout/NavMenu.razor

@@ -0,0 +1,52 @@
+@inject NavigationManager navigator
+@inject ShogiApi Api
+
+<div class="NavMenu PrimaryTheme ThemeVariant--Contrast">
+	<h1>Shogi</h1>
+	<p>
+		<a href="/">Home</a>
+	</p>
+
+	<AuthorizeView>
+		<p>
+			<a href="/search">Search</a>
+		</p>
+
+		<p>
+			<button class="href" @onclick="CreateSession">Create</button>
+		</p>
+	</AuthorizeView>
+
+	<div class="spacer" />
+
+	<AuthorizeView>
+		<Authorized>
+			<p>@context.User.Identity?.Name</p>
+			<p>
+				<a href="logout">Logout</a>
+			</p>
+		</Authorized>
+		<NotAuthorized>
+			<p>
+				<a href="login">Login</a>
+			</p>
+			<p>
+				<a href="register">Register</a>
+			</p>
+		</NotAuthorized>
+	</AuthorizeView>
+</div>
+
+
+@code {
+
+	async Task CreateSession()
+	{
+		var sessionId = await Api.PostSession();
+		if (!string.IsNullOrEmpty(sessionId))
+		{
+			navigator.NavigateTo($"/play/{sessionId}");
+		}
+	}
+
+}