Retrieve VolumeAttachments from cluster

We likely could benefit from retrieving `VolumeAttachment`s from clusters to catch these types of errors:

```
- apiVersion: storage.k8s.io/v1
kind: VolumeAttachment
metadata:
annotations:
csi.alpha.kubernetes.io/node-id: aks-node000
deletionGracePeriodSeconds: 0
finalizers:
- external-attacher/disk-csi-azure-com
name: csi-asdf
spec:
attacher: disk.csi.azure.com
nodeName: aks-node000
source:
persistentVolumeName: pvc-asdf
status:
attachError:
message: 'rpc error: code = Unknown desc = Attach volume /subscriptions/01234/resourceGroups/rg0/providers/Microsoft.Compute/disks/pvc-asdf
to instance aks-node000 failed with Retriable: true,
RetryAfter: 0s, HTTPStatusCode: -1, RawError: Code="VMExtensionProvisioningTimeout"
Message="Provisioning of VM extension AKSLinuxExtension has timed out. Extension
provisioning has taken too long to complete. The extension did not report
a message. More information on troubleshooting is available at https://aka.ms/vmextensionlinuxtroubleshoot"'
attached: false
detachError:
message: 'rpc error: code = Internal desc = Could not detach volume /subscriptions/01234/resourceGroups/rg0/providers/Microsoft.Compute/disks/pvc-asdf
from node aks-node0000: Retriable: true, RetryAfter: 0s,
HTTPStatusCode: -1, RawError: Code="VMExtensionProvisioningTimeout" Message="Provisioning
of VM extension AKSLinuxExtension has timed out. Extension provisioning has
taken too long to complete. The extension did not report a message. More information
on troubleshooting is available at https://aka.ms/vmextensionlinuxtroubleshoot"'
```