disk: DescribeDisks auto batching

[huww98]

What type of PR is this?

/kind feature
/kind cleanup

What this PR does / why we need it:

disk: introduce DiskStatusWaiter

A central place for all disks pending status changes (attaching/detaching).
Waiter will poll disk status in batch and wake up the caller if the status has changed.

The motivation is reducing OpenAPI call count, to avoid triggering throttling, thus improve system throughput.

Also include a simple fallback waiter to support multi-tanent use-case.

Shared disk support is best effort, since we cannot create new shared disks for test now.

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?

If AD-controller enabled, the number of DescribeDisks requests on a busy cluster will be reduced greatly.

Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.:

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

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[k8s-ci-robot]

Hi @huww98. Thanks for your PR.

I'm waiting for a kubernetes-sigs 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.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

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[huww98]

TODO: the ecsClient in waiter cannot update its credential.

[huww98]

I have observed that after AttachDisk returns, the status remains Available for a short period, so I'm not relying on disk.Status in this version.

[huww98]

/ok-to-test
I've worked around the credential refresh issue with a hook.

[huww98]

In this version, I issue exactly one DescribeDisk request every 2s. So, if the number of pending disks goes just above 100, the QPS will not be doubled suddenly. If 300 disks are pending, then the status of each disk will be updated every 6s, and the QPS of DescribeDisk should remains constant.

[huww98]

/auto-cc

[k8s-ci-robot]

PR needs rebase.

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