New config action that can create entities for each node type, media type, etc.

#3464550: Create config action which can create an entity for every bundle of another entity type added a pair of new config actions, createForEach and createForEachIfNotExists, which can be used to loop over bundle config entities -- node types, media types, taxonomy vocabularies, and so forth -- to create other config entities that are coupled to those bundles.

A classic use case is making every content type translatable. This requires creating a language.content_settings.node.TYPE entity for each node type. Previously, there was no way to do this with recipes or config actions. Now, you can do this:

config:
  actions:
    node.type.*:
      createForEach:
        language.content_settings.node.%bundle:
          target_entity_type_id: node
          target_bundle: %bundle

In this config action, the %bundle placeholder will be replaced with the ID of the node type being processed. For example, when processing a blog node type, it will create a corresponding language.content_settings.node.blog entity.

Let's say you want to create content settings and an image style for each content type. You can use createForEach to create multiple entities at once:

config:
  actions:
    node.type.*:
      createForEachIfNotExists:
        language.content_settings.node.%bundle:
          target_entity_type_id: node
          target_bundle: %bundle
        image.style.node_%bundle_thumbnail:
          label: 'Thumbnail for %label content'

For a blog content type, this will create both a language.content_settings.node.blog entity and an image.style.node_blog_thumbnail. In the array values (but not the keys) you can use the %label placeholder to insert the human-readable label of the bundle being processed.

Each derived entity is created exactly the same way the createIfNotExists and create actions do it -- you just provide an array of values to create the entity with. These actions will handle preexisting entities with the same ID the same way that the createIfNotExists and create actions do.