[Feature Request] Add capability in VitessShardTabletPool CRD to attach additional disks to each vttablet

[ajit-pendse]

Use cases where different disk is needed (e.g. for bin-logs) in each vttablet cannot be implemented with current structure. Capability similar to dataVolumeClaimTemplate used for data disk would be helpful to handle such use cases.

Current VitessShardTabletPool CRD allows attaching extraVolumes which can point to only one PVC per volume. This will lead to multiple pods trying to mount same PVC.