Rewrite lesson to be self-contained and not depend on the core of WebGoat for fetching users

Split the assignment into 2 assignments

webgoat-container/src/main/java/org/owasp/webgoat/users/WebGoatUser.java

@@ -34,15 +34,14 @@ public class WebGoatUser implements UserDetails {
     }
 
     public WebGoatUser(String username, String password) {
-        this.username = username;
-        this.password = password;
-        createUser();
+        this(username, password, ROLE_USER);
     }
 
     public WebGoatUser(String username, String password, String role) {
         this.username = username;
         this.password = password;
         this.role = role;
+        createUser();
     }