take storageclass for operator from single parameter

[boddumanohar]

Currently to set storage class for all the stateful resources within the operator we need to set them at 4 places:

this way.

--set controlplane.storageclass.name=local-hostpath \
--set controlplane.observability.minio.storageClass=local-hostpath \

--set prometheus.server.persistentVolume.storageClass=local-hostpath \
--set opensearch.persistence.storageClass=local-hostpath \

the first 2 are needed for the operator's own stateful set resources:

1. FDB resources
2. Prometheus

this PR eliminates the need for setting these 2 parameters

--set controlplane.storageclass.name=local-hostpath \ --> used for FDB
--set controlplane.observability.minio.storageClass=local-hostpath \ --> used for 

To idea is to have a single storage class for all the operator managed PVCs. At the moment, if the default storage class cannot be used we override the storage class parameter at

We don't expect customers to use to use different storage class for each of them.