Began transition to Vue3.

Implemented logging in and logging out.

Implemented authenticated http client.

Laid some groundwork for SCSS.

MultiShop/server/Models/ApplicationUser.cs

@@ -0,0 +1,12 @@
+using Microsoft.AspNetCore.Identity;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+
+namespace MultiShop.Models
+{
+    public class ApplicationUser : IdentityUser
+    {
+    }
+}