Include CSI volume snapshot information in velero backup describe (#2448)

* Add download methods for CSI objects

Signed-off-by: Nolan Brubaker <brubakern@vmware.com>

* Add support for downloading CSI volume objects

Signed-off-by: Nolan Brubaker <brubakern@vmware.com>

* Add new methods to mock.

Remove generated information from file since mockery no longer appears
to work. It isn't maintained anymore and doesn't support go module-based
projects.

Signed-off-by: Nolan Brubaker <brubakern@vmware.com>

* Add describe command for CSI

Signed-off-by: Nolan Brubaker <brubakern@vmware.com>

* Add csi package with helpers

Signed-off-by: Nolan Brubaker <brubakern@vmware.com>

* Remove duplicate import from server

Signed-off-by: Nolan Brubaker <brubakern@vmware.com>

* Remove CSI API that will not be used with describe

Signed-off-by: Nolan Brubaker <brubakern@vmware.com>

* Add VolumeSnapshotContents output to describe command

Signed-off-by: Nolan Brubaker <brubakern@vmware.com>

* Document NewCSIListOptions function

Signed-off-by: Nolan Brubaker <brubakern@vmware.com>

* Document csi package

Signed-off-by: Nolan Brubaker <brubakern@vmware.com>

* Remove stutter in function name

Signed-off-by: Nolan Brubaker <brubakern@vmware.com>

* Fix CI

Signed-off-by: Nolan Brubaker <brubakern@vmware.com>

* Fix nil pointer error when not using CSI snapshots

Signed-off-by: Nolan Brubaker <brubakern@vmware.com>

* Remove unused CSI download request kinds

Signed-off-by: Nolan Brubaker <brubakern@vmware.com>

* Add back mocks

Signed-off-by: Nolan Brubaker <brubakern@vmware.com>

* Change persistent volumes to velero-native snapshots

Signed-off-by: Nolan Brubaker <brubakern@vmware.com>

* Remove unused function

Signed-off-by: Nolan Brubaker <brubakern@vmware.com>

* Address review feedback

Signed-off-by: Nolan Brubaker <brubakern@vmware.com>

* Add changelog

Signed-off-by: Nolan Brubaker <brubakern@vmware.com>

* Remove unnecessary doc.go

Signed-off-by: Nolan Brubaker <brubakern@vmware.com>

pkg/cmd/server/server.go

@@ -28,7 +28,6 @@ import (
 	"sync"
 	"time"
 
-	snapshotterClientSet "github.com/kubernetes-csi/external-snapshotter/v2/pkg/client/clientset/versioned"
 	"github.com/pkg/errors"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/sirupsen/logrus"
@@ -229,7 +228,7 @@ type server struct {
 	dynamicClient                       dynamic.Interface
 	sharedInformerFactory               informers.SharedInformerFactory
 	csiSnapshotterSharedInformerFactory *CSIInformerFactoryWrapper
-	csiSnapshotClient                   *snapshotterClientSet.Clientset
+	csiSnapshotClient                   *snapshotv1beta1client.Clientset
 	ctx                                 context.Context
 	cancelFunc                          context.CancelFunc
 	logger                              logrus.FieldLogger