Some content wrappers are not passed to display suite layouts overridden twig templates

Problem/Motivation

I'm trying to update a existing site to drupal 8.3-rc1 and I have some overriden ds templates in my theme.

The content wrappers for the two column layout are missing so the markup displayed is "<>".
The 1 column layout is fine if not overriden. when you add a ds-1col.html.twig
that template won't have the ds_content_wrapper variable and just show the attributes as markup.

Proposed resolution

Change twig templates to get the variables in their new locations like ds-1col

BEFORE:

<{{ ds_content_wrapper }}{{ attributes.addClass('ds-1col', 'clearfix') }}>

  {{ title_suffix.contextual_links }}

  {{ ds_content }}

</{{ ds_content_wrapper }}>

AFTER:

<{{ settings.wrappers.ds_content }}{{ attributes.addClass('ds-1col', 'clearfix') }}>

  {{ title_suffix.contextual_links }}

  {{ content.ds_content }}

</{{ settings.wrappers.ds_content }}>

Remaining tasks

User interface changes

API changes

Data model changes