Add a basic integration test for the shipper Elasticsearch output. The test should:

1. Start Elasticsearch as a Docker container.
2. Start the shipper binary with an Elasticsearch output configured to write to the Elasticsearch Docker container.
3. Setup a single data stream as the target for the events that will be ingested during the test. https://www.elastic.co/guide/en/elasticsearch/reference/current/set-up-a-data-stream.html
4. Publish events to the shipper via the gRPC API and ensure they are ingested into the target data stream with the expected format.