feat: integrate angular-oauth2-oidc for authentication

- Added angular-oauth2-oidc package to package.json.
- Configured OAuth client in app.config.ts with resource server settings.
- Implemented login component with basic HTTP request to fetch products.
- Set up routing for the login component.
- Updated app component to initialize OAuth service and handle login.
- Modified default app settings to open and collapse sidenav by default.
- Removed placeholder content from app.html to streamline the initial view.

Web/themes/modernize/src/app/config.ts

@@ -6,6 +6,6 @@ export interface AppSettings {
 }
 
 export const defaults: AppSettings = {
-  sidenavOpened: false,
-  sidenavCollapsed: false,
+  sidenavOpened: true,
+  sidenavCollapsed: true,
 };