Issue #3424509 by godotislate, quietone, sorlov, smustgrave, benjifisher,...
Issue #3424509 by godotislate, quietone, sorlov, smustgrave, benjifisher, alexpott: Update MigratePluginManager to include both attribute and annotation class
* @section sec_destination Migrate API destination plugins
* Migrate API destination plugins implement
* \Drupal\migrate\Plugin\MigrateDestinationInterface and usually extend
* \Drupal\migrate\Plugin\migrate\destination\DestinationBase. They are
* annotated with \Drupal\migrate\Annotation\MigrateDestination annotation and
* must be in namespace subdirectory 'Plugin\migrate\destination' under the
* namespace of the module that defines them. Migrate API destination plugins
* are managed by the \Drupal\migrate\Plugin\MigrateDestinationPluginManager
* class.
* \Drupal\migrate\Plugin\migrate\destination\DestinationBase. They have the
* \Drupal\migrate\Attribute\MigrateDestination attribute and must be in
* namespace subdirectory 'Plugin\migrate\destination' under the namespace of
* the module that defines them. Migrate API destination plugins are managed by
* the \Drupal\migrate\Plugin\MigrateDestinationPluginManager class.
*
* @link https://api.drupal.org/api/drupal/namespace/Drupal!migrate!Plugin!migrate!destination List of destination plugins for Drupal configuration and content entities provided by the core Migrate module. @endlink