Replace approach that decorates core 'main_content_renderer.html' service

[Ateee89]

Package

next (Drupal module)

Describe the feature request

Approach should be changed to not decorate core's main_content_renderer.html service, but instead provide a normal preview route. There can be use cases where users want to see the entity view instead of the preview.

[mglaman]

There is also the overhead where Next.js is running for all pages because it decorates the renderer.