Handle update and delete of Block component config entities

👍

This should add \Drupal\Tests\experience_builder\Kernel\Plugin\ExperienceBuilder\ComponentSource\BlockComponentTest and test — by for example deleting a Menu config entity, which will result in \Drupal\system\Plugin\Derivative\SystemMenuBlock deriving one fewer block.

I bet there will be config dependency-related challenges 😇 In fact … I see that the necessary config dependencies are missing currently. For example:

uuid: 784eab71-dbfa-49da-b932-dc703a5de2f8
langcode: en
status: true
dependencies: {  }
label: 'Administration block'
id: block.system_menu_block.admin
provider: system
source: block
category: Menus
settings:
  plugin_id: 'system_menu_block:admin'
  default_settings:
    id: 'system_menu_block:admin'
    label: Administration
    label_display: ''
    provider: system
    level: 1
    depth: 0
    expand_all_items: true

😱

That

dependencies: {  }

should be

dependencies:
  config:
    - system.menu.admin

That is an oversight in bug when Block support was first added in 📌 Add support for Blocks as Components Active .