[ENHANCEMENT] Zeebe add support for additional Exporter Configuration

[felicijus]

Describe the use case:

The configuration of additional Zeebe exporters are currently not supported directly via the camunda-platform Helm Chart. The usage of custom exporters should be possible natively.

UseCases See:

• zeebe-redis-exporter
• zeebe-kafka-exporter
• zeebe-hazelcast-exporter

All of these examples of exporters expect the user to change the application.yaml of zeebe to something like this:

zeebe:
  broker:
    exporters:
      <exporter>:
        className: <className>
        jarPath: <jarPath>
        args:
          <key: value>

Describe the enhancement/feature:

Currently camunda-platform Helm Charts only supports the addition of Zeebe exporters by using initContainer and environment variables. Or manually changing the Zeebe application.yaml.

This could be changed by providing a property like additionalExporterConfig inside values.yaml:

zeebe:
  additionalExporterConfig:
      redis:
        className: "io.zeebe.redis.exporter.RedisExporter"
        jarPath: "/usr/local/zeebe/lib/zeebe-redis-exporter-1.0.2-jar-with-dependencies.jar"
        args:
          remoteAddress: "redis://redis:6379"
      
      kafka:
        className: "io.zeebe.kafka.exporter.KafkaExporter"
        jarPath: "/usr/local/zeebe/lib/zeebe-kafka-exporter-1.0.2-jar-with-dependencies.jar"
        args:
          bootstrapServers: "kafka:9092"

Desired outcome and acceptance tests:

Contents of a property like additionalExporterConfig should be rendered by the Helm Chart into the Zeebe configmap inside application.yaml to support additional exporters.