split CMVFS module into generic CSI module

parameterize the container used as the CSI plugin and move out CVMFS specific options into a parent module
Add:
```hcl
resource "kubernetes_csi_driver" "driver" {
  metadata {
    name = var.name
  }

  spec {
    attach_required        = var.attach_required
  }
}
```
and optionally deploy attacher depending on var.attach_required