Create queue worker to create media for asset_created webhook.

Problem/Motivation

Create a lean queue worker for DAM webhooks.

It should handle asset_created, dispatch Symfony events for all event types, and deduplicate replayed deliveries so duplicate deliveries are silently discarded.

As a developer, I want a lean queue worker that handles asset_created, dispatches Symfony events for all event types, and deduplicates replayed deliveries, so that third-party code can react to all webhook events and duplicate deliveries are silently discarded.

asset_deleted, asset_metadata_value_updated, and asset_version_added are now handled synchronously in WebhookReceiverController and will never be enqueued here.

This worker's primary responsibilities are asset_created (log + no-op by default) and Symfony event dispatching for all event types.

Acceptance criteria

• Extends QueueWorkerBase, ID acquia_dam_webhook_events, cron = {"time" = 30}
• asset_created → log + no-op (Symfony event below allows site code to react, e.g. auto-import)
• No asset sync or unpublish logic — this is handled inline in WebhookReceiverController
• Delivery ID dedup via keyvalue.expirable collection acquia_dam_webhooks.webhook_delivery_ids (24h TTL)
• Symfony events dispatched for all event types: AcquiaDamWebhookEvents::ASSET_VERSION_ADDED / ASSET_METADATA_VALUE_UPDATED / ASSET_DELETED / ASSET_CREATED constants
• AcquiaDamWebhookEvent typed accessors:
  • getPayload()
  • getAssetId()
  • getEventType()
  • getDeliveryId()
  • getWebhookConfigurationId()
  • getDateCreated()
  • getEventContext()
• Subscriber exceptions caught + logged — never re-queue the item
• Only 3 injected services: LoggerChannelInterface, EventDispatcherInterface, KeyValueExpirableFactoryInterface