Option to return Drupal template instead of HTML from Frontend module

[dgading]

Developer Story

As a developer I want to access drupalSettings when initially loading a frontend page. I also want to be able to use Drupal modules to set information in the page head section and return customized headers from Drupal. I also want to be able to tell the status of the current user on the page, for example are they an authorized user or anonymous.

Acceptance Criteria

Using a config setting in frontend.config I can switch between returning a Drupal twig template that loads my React app and the current setup where just the HTML is returned when visiting a catalog page.

Dependency

The reason for the options listed above is needed as the frontend application will need to adjust its build process and index.html files to remove the non body content if using the new Drupal template.