Body field text_with_summary picker in wizard WIP mostly done.

WIP mostly completed for a body field picker. Just need to add processing the body field itself in case it is custom or similar. Wizard seems about ready. #3516531

migrations/wordpress_content.yml

@@ -72,9 +72,15 @@ process:
     message: 'Cannot import empty titles. This may include trashed posts from the WordPress import file.'
   # @todo: Will need process plugin to rewrite links/img refs.
   # @link https://www.drupal.org/node/2742279
-  'body/value': content
-  'body/summary': excerpt
+  '_content/value':
+    - plugin: get
+      source: content
+  '_content/summary':
+    - plugin: get
+      source: excerpt
   created:
+    # @todo This field is not fault tolerant. May be fatal errors.
+    # @link https://www.drupal.org/project/wordpress_migrate/issues/3516516
     plugin: callback
     source: post_date
     callable: strtotime