BlazorShared and Services (#430)

* Service to Services

* Change Shared project to BlazorShared

* change refrerances to BlazorShared

src/BlazorShared/Authorization/Constants.cs

@@ -0,0 +1,14 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace BlazorShared.Authorization
+{
+    public class Constants
+    {
+        public static class Roles
+        {
+            public const string ADMINISTRATORS = "Administrators";
+        }
+    }
+}