Remove out-of-scope changes for multi-level images

app/controllers/admin/application_settings_controller.rb

app/controllers/admin/container_registry_controller.rb

app/models/application_setting.rb

app/views/admin/container_registry/show.html.haml

app/views/admin/dashboard/_head.html.haml

config/routes/admin.rb

...ontainer_registry_access_token_to_application_settings.rb

doc/administration/container_registry.md

lib/api/api.rb

lib/api/helpers.rb

lib/api/registry_events.rb

lib/container_registry/ROADMAP.md