enrich-kinesis: add integration tests with localstack and testcontainers

[benjben]

Add 3 integration tests for enrich-kinesis with testcontainers and localstack:

1. One that generates and sends collector payloads to the input of Enrich and checks that the output streams contain the expected number of enriched events and bad rows
2. One that checks that Enrich can initialize with the minimal config example
3. One that checks that Enrich exits gracefully when it receives a SIGTERM

The Docker image of enrich-kinesis has to be published locally by sbt before executing the tests.

sbt "project kinesis" IntegrationTest/test runs the tests.