Add volume builder helper to operator-rs

[nightkr]

Description

Similar to the secret operator, the listener operator requires volume mounts in each pod. This should be added to the operator-rs for all operators to use (similar to the secret volume builder).

This is an example in the Kafka operator on how to configure a volume for the listener operator: https://github.com/stackabletech/kafka-operator/blob/d963287af3ba8f21039751e6af4931ca8925fb6b/rust/operator/src/kafka_controller.rs#L649.

Acceptence

• The operator builder module (pod/volume.rs) is extended with a ListenerOperatorVolumeSourceBuilder similar to the [secret volume builder](https://github.com/stackabletech/operator-rs/blob/main/src/builder/pod/volume.rs#L270
• The Kafka spike is adapted and tested
• Optional: Unit tests are added