feat: add oidc authorization code with pkce login flow

frontend/src/app/app.routes.ts

@@ -1,3 +1,4 @@
 import { Routes } from '@angular/router';
+import { Callback } from './auth/callback/callback';
 
-export const routes: Routes = [];
+export const routes: Routes = [{ path: 'auth/callback', component: Callback }];