Support External Events: Kafka, RabbitMQ, and More

[taubyte0]

Currently, Tau functions are limited to HTTP triggers for external events. To enhance functionality, we should extend support to include event sources like Kafka and RabbitMQ, among others.

• Kafka: Use the segmentio/kafka-go package for integration.
• RabbitMQ: Use the rabbitmq/amqp091-go package for integration.

Proposed Options for Implementation:

1. Cluster-Based Configuration:
   Configure external event sources and assign them to specific clusters, enabling broader accessibility and scaling.

2. Organization-Specific Configuration:
   Configure event sources directly within Tau, restricting their usage to a single organization. This option offers simplicity and a clear boundary for resource usage.

Both approaches can be implemented simultaneously to provide flexibility while meeting different use cases.