Allow tenants to have multiple volume claim templates

[AlexFangSW]

Is your feature request related to a problem? Please describe.

Our current use case is combining the 'bucket notification' with AMQP.

To prevent having lost messages, we also used the 'queue directory' setting when creating a AMQP event destination.

Here's the problem: There doesn't seem to be a nice way to persist messages stored in 'queue directory'.

We understand that there is an additionalVolumes section. But most of the options there will result in multiple pods sharing the same persistent volume, and the volumeClaimTemplates setting is in the ephemeral section...

We are not sure how MinIO works internally, but multiple pods writing and reading to the same persistent volume sounds like problem.

Describe the solution you'd like

Add volumeClaimTemplates setting in additionalVolumes that is not in the ephemeral section.

Describe alternatives you've considered

Additional context

Our current solution is to use hostPath in additionalVolumes section.

With MinIO deployed on different nodes, this results in pods having they're own persistent volumes.

But we really don't want pods to use hostPath.

[cesnietor]

We'll discuss this internally.