feat: archive on delete support

[navilg]

What type of PR is this?

Uncomment only one /kind <> line, hit enter to put that in a new line, and remove leading whitespaces from that line:

/kind feature

What this PR does / why we need it:

This allows parameter onDelete: archive which will archive the the volume in nfs server when PV is deleted. Other two values, delete and retain are retained and serves their purpose.

This is helpful when we want to retain the nfs volume upon deletion of PV, but we also want to distinguish/separate the volume name in nfs server for deleted PVs from the in-use nfs volumes. This will prefix archived- in the folder name of PV in nfs server when PV is deleted.

Which issue(s) this PR fixes:

Fixes #522

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

To archive the volumes on deletion of PV, create storage class with parameter `ondelete: archive`. For e.g.

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: nfs-csi
mountOptions:
- nfsvers=4.1
parameters:
  onDelete: archive    # <----------------------------------------------------- Archive on delete policy
  server: mynfsserver.io
  share: /var/nfs/k8s_pvs
provisioner: nfs.csi.k8s.io
reclaimPolicy: Delete
volumeBindingMode: WaitForFirstConsumer


To make the archive on deletion behaviour default, install with below value set in helm.

--set controller.defaultOnDeletePolicy=archive

[k8s-ci-robot]

Hi @navilg. Thanks for your PR.

I'm waiting for a kubernetes-csi member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

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[andyzhangx]

/ok-to-test

[andyzhangx]

@navilg could you fix the ut failure? thanks.

[coveralls]

Pull Request Test Coverage Report for Build 6798767808

Warning: This coverage report may be inaccurate.

We've detected an issue with your CI configuration that might affect the accuracy of this pull request's coverage report.
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A quick fix for this PR: rebase it; your next report should be accurate.

• 17 of 21 (80.95%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.3%) to 78.277%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
pkg/nfs/controllerserver.go	17	21	80.95%

Totals
Change from base Build 6588984870:	0.3%
Covered Lines:	854
Relevant Lines:	1091

---

💛 - Coveralls

[navilg]

@andyzhangx Thanks for fixing ut. I could not make time last weekend.

[andyzhangx]

/lgtm

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: andyzhangx, navilg

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